DIR® iS Evidence-Based
DIRFloortime® Research, Science, and Evidence-base
DIRFloortime® Research, Science, & Evidence
DIRFloortime has the strongest research of any intervention to support its effectiveness in improving the core challenges of autism including relating, interacting, and communicating while decreasing caregiver stress and improving parent-child relationships.
DIR® and DIRFloortime® Evidence-Base Quick Facts
The following is a brief sample of the evidence-base supporting DIR and DIRFloortime (Floortime). The research includes the highest levels of evidence and includes case studies, group design studies, randomized controlled trial studies, and systematic reviews. Unlike behavioral approaches which narrowly focus on specific behaviors, DIR is an interdisciplinary, individualized, whole-child, developmental approach that is broad in both its approach and its impact.
Multiple randomized-controlled studies were published since 2011 identifying statistically significant improvements for children with autism who used Floortime versus traditional behavioral approaches (Solomon, et. al., 2014; Casenheiser, Shanker &Steiben, 2011; Lal and Chhabria, 2013; Pajareya and Kopmaneejumruslers, 2011, Pajareya et. al., 2019
Solomon, Necheles, Ferch, and Bruckman (2007) conducted a pre-post survey of the Play and Language for Autistic Youngsters (PLAY) Project Home Consultation program. This program is a Floortime program. Results indicated statistically significant improvement in the children’s Functional Developmental Levels and 100% of the parents reported satisfaction in participating.
The cost associated with the DIRFloortime-based weekly intervention program as described in Casenhiser et al. (2012) is approximately $5000 per child per year, which is considerably less than the estimates of therapy for most therapist-delivered programs that typically provide 20–30 weekly hours of treatment (Flanders et al., 2005; Motiwala et al., 2006).
Case studies have also been effective in supporting the use of DIRFloortime with children with autism. Dionne and Martini (2011) demonstrated statistically significant improvement in communication between parent and child. Wieder and Greenspan (1997, 2005) did comprehensive case studied that spanned from 8-15 years. These studies supported the long-lasting results DIRFloortime had on individual child skills, as well as the emotional connections the families were able to develop over time using this approach.
Floortime and related DIR-based approaches are listed in evidence-based treatment reviews. For example, the Journal of Clinical Child and Adolescent Psychology published an article entitled, "Evidenced Base Update for Autism Spectrum Disorder" where they categorized Floortime as a "Developmental Social Pragmatic (DSP) Parent Training" and listed focused DSP Parent Training in their second level evidence base category indicating it as "Probably Efficacious." (Smith & Iadarola, 2015) In addition, a systematic review of developmental social pragmatic approaches including DIRFloortime was published in January, 2019 that supported the efficacy of developmental social pragmatic approaches for children with autism (Binns and Cardy, 2019).
Not only is the research supporting Floortime expanding, there is increasing research, analysis, and reviews that are raising questions about the research on ABA and behavioral approaches. In the recent 2020 Project AIM: Autism intervention meta-analysis for studies of young children published in the American Psychological Association's Psychological Bulletin they found that developmental approaches had stronger evidence to support effectiveness than behavioral approaches. Also, in a recent report by the US Department of Defense on the TRICARE Autism Care Demonstration (this is an ABA benefit that was provided to children covered under the benefit) they reported that 76% of those that received the services had little to no change and 9% actually worsened. (TRICARE is the health insurance coverage for many in the US military and Department of Defense.)
In a January, 2020 report by the American Academy of Pediatrics entitled "Identification, Evaluation, and Management of Children with Autism Spectrum Disorder", they stated, "Intervention for young children also may be derived from developmental theory, which is focused on the relationship between the caregiver’s level of responsiveness and the child’s development of social communication. Through interaction with others, children learn to communicate, regulate emotions, and establish a foundation for increasingly complex thinking and social interaction. Therefore, developmental models designed to promote social development in children with ASD are focused on the relationship between the child with ASD and his or her caregiver through coaching to help increase responsiveness to the adult (ie, the interventionist or parent or caregiver) through imitating, expanding on, or joining into child-initiated play activities. This approach may address core symptoms of ASD, such as joint attention, imitation, and affective social engagement. Developmental models for intervention are focused on teaching adults to engage in nondirective interactive strategies to foster interaction and development of communication in the context of play. One such approach is known as DIRFloortime (The Developmental, Individual Differences, and Relationship-Based model)." (Hyman et. al., 2020)
In an article published in the Journal of the American Medical Association in November, 2020 entitled, “Intervention Recommendations for Children with Autism in Light of a Changing Evidence Base” they recommended that pediatricians need to consider recommending a wider range of options to parents. In regards to the changing evidence based, they reported, “There has been a recent precipitous increase in both the quantity and quality of research examining interventions for young children with autism. From 2011 to 2018, the reported number of randomized clinical trials (RCTs) of interventions for young children with autism increased from 2 to 48.7 To summarize this transforming evidence base, we systematically reviewed and meta-analyzed 150 reports of 130 studies, 87 of which were RCTs, which collectively reported effect sizes for 1615 outcomes, representing 6240 young children with autism.2 Several findings emerged from this research, but 2 are of direct relevance to pediatricians directing families to services and supports following diagnosis. First, 3 intervention approaches that, at present, are not commonly recommended have garnered more substantial empirical support from RCTs relative to behavioral interventions. These are naturalistic developmental behavioral interventions (NDBIs) and developmental interventions. Al-though distinct from one another, these interventions are alike in that they are provided in children’s natural contexts (eg, everyday interactions with caregivers) and their learning targets are guided by early developmental sequences. These attributes may make them preferable to families, since they are less likely to disrupt and separate children from family routines than more structured clinician-led interventions.” (Sandbank et. al., 2020)
The evidence is strong and building – DIRFloortime works!
Click here for this information in a document with all references included.
Click here for a simple fact sheet on the evidence-base for DIR/DIRFloortime that includes all of the information above and all of the citations.
Recent Research ON dirfLOORTIME
The Evidence to Support DIRFloortime® Continues to Build
Establishing the evidence base behind DIR and DIRFloortime/Floortime is not as easy as in some approaches. DIR is an interdisciplinary, individualized, whole-child, developmental approach that is broad in both its approach and its impact. Unlike behavioral approaches that can simply show that a specific behavior that has been targeted to increase or decrease has changed, DIR is focused on improving the whole child in a wide range of ways. Nevertheless, the research continues to build to support DIR and the DIRFloortime approach.
Here are a few recent examples:
These recent studies offer more evidence of how effective and culturally appropriate DIRFloortime is in helping children and families around the world:
Pajareya, K, Sutchritpongsa, S, Kongkasuwan, R. (2019) DIR/Floortime® Parent Training Intervention for Children with Developmental Disabilities: a Randomized Controlled Trial. Siriraj Medical Journal. 2019. 71(5), 331-338.
Binns, A. and Cardy, J.0. (2019), Developmental social pragmatic interventions for preschoolers with autism spectrum disorder: A systematic review. Autism and Developmental Language Impairments. 2019 Jan; Vol 4(1), 1-18,
Solomon, R., Van Egeren, L., Mahoney, G., Quon Huber, M., Zimmerman, P. (2014). PLAY Project Home Consultation Intervention Program for Young Children With Autism Spectrum Disorders: A Randomized Controlled Trial. Journal of Developmental and Behavioral Pediatrics, 35(8), 475-485. http://www.playproject.org/assets/PLAY_Project_Home_Consultation_Intervention.1.pdf
Casenhiser D.M., Shanker, S., Stieben J. Learning Through Interaction in Children with Autism: Preliminary Data from a Social-Communication-Based Intervention. Autism, published online September 26, 2011.
Pajareya K, Kopmaneejumruslers K. A pilot randomized controlled trial of DIR/Floortime parent training intervention for pre-school children with autistic spectrum disorders. Autism, published online before print, June 13, 2011.
Casenhiser DM, Binns A, McGill F, Morderer O, Shanker SG. (2015). Measuring and supportinglanguage function for children with autism: evidence from a randomized controltrial of a social-interaction-based therapy. Journal of Autism and Developmental Disorders, 2015 Mar; 45(3):846-57
Sealy, J. and Glovinsky, I. P. (2016), Strengthening the Reflective Functioning Capacitiesof Parents Who have a Child with a Neurodevelopmental Disability through a Brief,Relationship-Focused Intervention. Infant Mental Health Journal. Doi: 10.1002/imhj.21557.
Christian, G (2011). A Person-Centered Approach to Problem Behavior: Using DIR®/Floortime with Adults Who Have Severe Developmental Delays. The NADD Bulletin, 2011, March/April, 14(2), 21-31.
Mok, J.W.S. and Chung, K.H. (2014). Application ofDIR/Floortime Model in the Psychiatric Service for Very Young Children with Autism in Hong Kong. Hong Kong Journal of Mental Health. 2014, 40(1), 23-30.
Binns, A, Hutchinson, L, and Oram Cardy, J (2018). The speech-language pathologist;s role in supporting thedevelopment of self-regulation: A review and tutorial. Journal of Communication Disorders (2018) 78, 1-17
Guiot, G, Meini, C, and Sindelar, M.T. (2012). Autismo e musica: il modello Floortime nei disturbi della comunicazione e della relazione. Difficoltà di apprendimento. 17(3), 103-113.
Sandbank, M., Bottema-Beutel, K., Crowley, S., Cassidy, M., Dunham, K., Feldman, J. I., Crank, J., Albarran, S. A., Raj, S., Mahbub, P., & Woynaroski, T. G. (2020). Project AIM: Autism intervention meta-analysis for studies of young children. Psychological Bulletin, 146(1), 1–29. https://doi.org/10.1037/bul0000215
Recent Relevant Evidence-Base Practice Reviews
The National Clearinghouse on Autism Evidence & Practice lists Parent-Implemented Interventions such as Floortime as Evidence-Based Practices in their most recent edition of the Evidence Based Practices for Children, Youth, and Young Adults with Autism.
In the Project AIM: Autism intervention meta-analysis for studies of young children. Psychological Bulletin, 146(1), 1–29. https://doi.org/10.1037/bul0000215 they found that developmental approaches had stronger evidence to support effectiveness than behavioral approaches.
The European Society for Child and Adolescent Psychiatry practice guidance for autism: a summary of evidence-based recommendations for diagnosis and treatment indicates that "At the present time, the strongest evidence for interventions for young autistic children comes from large-scale, randomised trials of developmentally based approaches designed to facilitate social communication between very young children and their parents. The main focus is on adult–child synchrony, with parents learning to respond to their child’s communicative cues in ways that encourage spontaneous communication, and create opportunities for shared attention, child initiations, and spontaneous play."
2010 Centers for Medicaid and Medicare Commissioned IMPAQ Report on Autism Services (This report preceded all of the RCT studies on Floortime and still listed Developmental Relationship-based Approaches as a level 2 emerging evidence-based intervention.)
INTERESTING RELATED STUDIES
A study out of New York University found that the intense interests that often accompany autism in adults can not only be helpful to their self-regulation, but also in finding fulfilling career paths. Read about it HERE.
A research study calls into question the practice of defaulting to Early intensive behavioral intervention (EIBI) and more recently, the naturalist developmental behavioral intervention (NDBI) in favor of strengths-based approaches, based on the latest neuroscience autism-related research. You can see the study HERE.
In Floortime, we seek to maximize the number of "circles of communication" during the Floortime process. This back-and-forth communication helps the brain develop. Check out this study:
Functional Emotional Assessment Scale
The Functional Emotional Assessment Scale by Stanley Greenspan, Georgia DeGangi, & Serena Wieder enables clinicians, educators, and researchers to observe and measure emotional and social functioning in infants, young children, and their families. Historically, the complexity of emotional functioning has been difficult to measure and assess. The FEAS meets this longstanding need of the field. The FEAS conceptualizes, operationalizes, and measures in a reliable and valid manner:
The full range of emotional functioning of infants, young children, and their families.
Naturally occurring emotional interactions between infants, children, and caregivers in a variety of settings, including home and school.
Both easily observable emotional behaviors and the subtle, more difficult to measure, deeper levels of emotional functioning.
Download the Book and Score Sheets (FREE):
oTHER DIR Related Research
Gernsbacher M.A., (2006). Toward a behavior of reciprocity. Journal of Developmental Processes, 1, 139-152. http://psych.wisc.edu/lang/pdf/gernsbacher_reciprocity.pdf
Gernsbacher has shown that intervention can change the way parents interact to increase reciprocity and that these changes are correlated with changes in social engagement and in language.
Kasari et al. 2008 used a randomized, controlled trial looking at joint attention and symbolic play in 58 children with autism. Results indicate that expressive language gains were greater for treatment groups that used developmental approaches compared with the control group that was based only on behavioral principles.
Kasari, Connie; Paparella, Tanya; Freeman, Stephanny; Jahromi, Laudan B. “Language outcome in autism: Randomized comparison of joint attention and play interventions.” Journal of Consulting and Clinical Psychology. Vol. 76(1), Feb 2008, 125-137.
Affleck, G., et al. (2001). Promise of relationship-focused early intervention in developmental disabilities. Journal of Special Education, 16, 413-430.
Dominguez, G. Dominguez, J., Stieben, J. & Shanker, S. (2013), The Imaginary part of coherency in autism: Differences in cortical functional connectivity in preschool children, PLOS ONE.
Kim, J. and Mahoney, G. (2005). The effects of relationship focused intervention on Korean parents and their young children with disabilities. Research in Developmental Disabilities, 26, 117-130.
Mahoney, G. & Perales, F. (2003). Using relationship-focused intervention to enhance the social-emotional functioning of young children with autism spectrum disorders. Topics in Early Childhood Special Education, 23, 74-86.
Mahoney, G., and F. Perales. (2004). “Relationship-focused early intervention with children with pervasive developmental disorders and other disabilities: a comparative study.” Journal of Developmental & Behavioral Pediatrics 26, 77-85.
Shanker, S (2012) Calm Alert and Learning: Classroom Strategies for Self-Regulation. New York: Pearson.
Shanker, S (2013) Emotion regulation through the ages. In T. Racine & A. Foolen (eds.), Moving Ourselves.
Shanker, S and J Stieben (2009), ‘The Roots of Mindblindness’, in Ivan Leudar (ed.), Against Theory of Mind. London, Palgrave Macmillan.
Shanker, S & Casenhiser, D (2013), Reducing the Effort in Effortful Control. In The Role and use of Conceptual Analysis in Psychology, T. Racine & K Slaney (Eds.). Palgrave.
Dr. Nancy Minishew presented neurological findings regarding the differences in persons with and without autism, and suggested that affect-based interventions are critical to address the underlying neurological core deficits in autism.
Minishew, N.J. and Williams, D.L. (2008) Brain behavior connections in autism. In K.D. Buron and P. Wolfberg (Eds.), Educating learners on the autism spectrum: Translating theory into meaningful practice. Shawnee, K.S.: Autism Asperger Publishing Co.
Casenhiser, D. , Shanker, S. and Stieben, J. (2011) Learning through interaction in children with autism: Preliminary data from a social-communication-based intervention, Autism: The international journal of research and practice., 1-22. This ongoing research study by Casenhiser, Stieben and Shanker at the Milton and Ethel Harris Research Institute at York University is investigating behavioral and neurophysiological outcomes of intensive social-affect-relationship-based intervention known as MEHRIT, using both ERP and EEG measurements. A preliminary report of a randomized controlled trial with results of the first year of a two-year intervention shows significant effectiveness of the ‘social-communication approach’ based upon this framework. They have found significant improvements in social interaction skills after 2 hours/week of DIR-based therapy for one year. Two studies of the results of imaging studies have now been submitted for publication:
Casenhiser, D.M., Binns, A., McGill, F., Morderer, O., & Shanker, S.G. (submitted a) Measuring and Supporting Language Function for Children with Autism: Evidence from an RCT of social-interaction-based therapy.
Casenhiser, D.M., Shanker, S.G. & Hoffman, J. (submitted b) Improvements in parental stress following training in a social-interaction-based treatment for autism.
Sigman, M., Siller, M. (2003). The Origin of Language: Evidence from Longitudinal Research in Autism. Journal of Developmental and Learning Disorders, 7 1-14.
Williams, D.I. (2008). What neuroscience has taught us about autism. Zero to Three. 11-17
Center on the Developing Child at Harvard University (2011). Building the Brain’s “Air Traffic Control” System: How Early Experiences Shape the development of Executive Function: Working Paper No. 11. http://wwwdevelopingchild.harvard.edu. “Children with special needs, such as those associated with autism…may have particular difficulty with executive functioning demands” P. 6.
Developmental Patterns and Outcomes in Infants and Children with Disorders in Relating and Communicating: A Chart Review of 200 Cases of Children with Autistic Spectrum Diagnoses by Stanley I. Greenspan, M.D., & Serena Wieder, Ph.D.
Charts of 200 children who were diagnosed with autistic spectrum disorder were reviewed. The goal of the review was to reveal patterns in presenting symptoms, underlying processing difficulties, early development and response to intervention in order to generate hypotheses for future studies. The chart review suggests that a number of children with autistic spectrum diagnoses are, with an appropriate intervention program, capable of empathy, affective reciprocity, creative thinking, and healthy peer relationships; that an intervention approach that focuses on individual differences, developmental level, and affective interaction may be especially promising; and that there are different underlying processing patterns with a difficulty in connecting affect and sequencing capacities as a possible common denominator. It also suggests that there is an early marker, the difficulty in engaging in complex purposeful gestural communication, and that contrary to traditional beliefs, a significant number of children may have relatively better functioning in the first year with a regression in the second and third years. This review also suggest that difficulties with relating and intimacy are often secondary to underlying processing disturbances. Many children can become quite loving and caring, thoughtful, and creative, suggesting a need to change the criteria for diagnosing these disorders. To read the complete article please click here.
The Bridge Project 2009 is a joint effort of the Bridge Collaborative, a group comprised of UCSD, Rady Children's Hospital, the San Diego Regional Center, the Harbor Regional Center (Torrance, Long Beach), Kaiser Permanente, parents, and private providers, and others. They were awarded a $250,000 NIH R01 grant for a pilot study, with a clear path toward a $2,500,000 grant, to implement evidenced based screening and intervention in Southern California. They have chosen Project ImPACT and added components of engagement, individual differences, and reflective process
The P.L.A.Y. Project Awarded $1.85 Million Grant from the National Institute of Mental Health Grant to Fund Research on Play-based Early Intervention for Autism; Confront Increasing Numbers of Young Children on the Spectrum
Ann Arbor, Mich.—September 24, 2009—Through the support of a $1.85 million grant from the National Institute of Mental Health (NIMH), Richard Solomon, MD, is conducting a three-year study of The Play and Language for Autistic Youngsters (P.L.A.Y.) Project Home Consulting model, a parent-training program that addresses the need for intensive early intervention for young children on the autism spectrum. Developed by Dr. Solomon, P.L.A.Y. is a practical, family-friendly application of renowned child psychiatrist Dr. Stanley Greenspan’s Developmental, Individual-differences, Relationship-based (DIR) framework, popularly known as DIR/Floortime. Through structured monthly home visits focused on modeling, coaching and video feedback, consultants train parents to engage their child with autism in ways that promote emotional connection and communication. By training parents to participate in their child’s intervention, the program also promises to be cost-effective. The P.L.A.Y. Project costs under $4,000 per year, in comparison with other interventions that cost $40,000 to $60,000 per year. Read Complete Press Release
DIR/Floortime and Autism Spectrum Disorders: Overview and Summary of Scientific and Public Support
(An older 2010 overview, but some good information and links still...)
The Developmental, Individual Difference, Relationship-based (DIR/Floortime) Model is a developmental, interdisciplinary framework that enables clinicians, parents and educators to construct a comprehensive assessment and intervention program based on the child’s and family’s unique developmental profile. It enables the individual working with the child to enter the child’s world, bring the child into a shared world, and, from there, interact with the child in ways that build the foundations for social, emotional, and intellectual development. The profile includes understanding the child’s emotional, social, and intellectual level; individual differences in motor, sensory, and language functioning; and the existing caregiver, child and family functioning and interaction patterns.
Built on years of research in developmental psychology that underscores the importance of early relationships and family functioning, DIR Floortime also integrates research contributions from various disciplines, such as speech and language pathology, occupational therapy, social work, and marriage and family therapy. Neuroscience research lends further support to developmental interventions. Early relationships and reciprocal interactions between infants and caregivers appear vital for the creation of healthy brain development, including for example wiring the pre-frontal cortex. These diverse contributions provide a rich structure so that clinicians can understand the child and family’s unique profile. This understanding is crucial for implementing a comprehensive assessment and intervention program for children with autism spectrum disorder (ASD) as well as related special needs conditions. View this 2010 article.
Guidelines for Early Identification, Screening, and Clinical Management of Children With Autism Spectrum Disorders by Stanley I. Greenspan, MD, T. Berry Brazelton, MD, José Cordero, MD, MPH, Richard Solomon, MD, MPH, FAAP, Margaret L. Bauman, MD, FAANP, Ricki Robinson, MD, MPH, FAAP, Stuart Shanker, DPhil and Cecilia Breinbauer, MD, MPH
Pilot Study of a Parent Training Program for Young Children with Autism. The PLAY Project Home Consultation Program by Richard Solomon, Jonathan Nechels, Courtney Ferch &
David Bruckman Autism © 2007 SAGE Publications and The National Autistic Society Vol 11(3) 205–224
Sixty-eight children completed the 8–12 month program. Parents were encouraged to deliver 15 hours per week of 1:1 interaction. Pre/post ratings of videotapes by blind raters using the Functional Emotional Assessment Scale (FEAS) showed significant increases (p ≤ 0.0001) in child subscale scores. Translated clinically, 45.5 percent of children made good to very good functional developmental progress. There were no significant differences between parents in the FEAS subscale scores at either preor post intervention and all parents scored at levels suggesting they would be effective in working with their children. Overall satisfaction with PPHC was 90 percent. Average cost of intervention was $2500/year. Despite important limitations, this pilot study of The PLAY Project Home Consulting model suggests that the model has potential to be a cost-effective intervention for young children with autism. To read the complete article please click here.
National Academy of Sciences Report, "Excerpts from Engaging Autism Using the Floortime Approach to Help Children Relate, Communicate, and Think" by Stanley I. Greenspan, M.D., Serena Wieder, Ph.D. A Merloyd Lawrence Book Da Capo Lifelong Books A Member of the Perseus Books Group
The National Academy of Sciences (NAS), in its report“ Educating Children with Autism” (National Academy of Sciences, Committee on Educational Interventions for Children with Autism, NRC, 2001), states that there is research support for a number of approaches, including DIR/Floortime and behavioral interventions, but that there are no proven “relationships between any particular intervention and children’s progress” (page 5) and “no adequate comparisons of different comprehensive treatments” (page 8). The report concludes that effective interventions vary depending on an individual child’s and family’s needs. The NAS analysis further indicates that behavioral interventions are moving toward naturalistic, spontaneous types of learning situations that follow the child’s interests, and note that “studies have reported that naturalistic approaches are more effective than traditional discrete trial at leading to generalization of language gains to natural contexts: (Koegel, Camarata, Valdez Menchaca, and Koegel, 1998; McGee, Krantz, and McClannahan, 1985). To read the rest complete article please click here.
A Ten to Fifteen Year Follow-Up of a Subgroup of Children with Autism Spectrum Disorders (ASD) Who Received a Comprehensive Developmental, Individual-Difference, Relationship-Based (DIR) Approach By Dr. Stanley I. Greenspan & Dr. Serena Wieder
A follow-up study of 16 children diagnosed with an autistic spectrum disorder (ASD) revealed that with the DIRFloortime approach, a subgroup of children with ASD can become empathetic, creative, and reflective, with healthy peer relationships and solid academic skills. This suggests that some children with ASD can overcome challenges and reach levels of development formerly thought unattainable with a family-oriented approach that focuses on the building blocks of relating, communicating, and thinking. To read the complete article please click here
Relationship Focused Early Intervention With Children With Pervasive Developmental Disorders and Other Disabilities: A Comparative Study By Gerald Mahoney, Ph.D & Frida Perales, M.Ed.
This study compares the effects of relationship-focused early intervention on toddlers and preschool-age children who were classified as having either pervasive developmental disorders (PDDs) (N = 20) or developmental disabilities (DDs) (N = 30). The intervention was conducted over a 1-year period through weekly individual parent-child sessions. It focused on helping parents use responsive teaching strategies to encourage their children to acquire and use pivotal developmental behaviors that addressed their individualized developmental needs. Before and after comparisons indicated significant increases in parents’ responsiveness and children’s pivotal behavior. Both groups of children made significant improvements in their cognitive, communication, and socioemotional functioning. However, children with PDDs made statistically greater improvements on the developmental measures than children with DDs. On several developmental measures, children’s improvements were related to increases in both their parents’ responsiveness and their own pivotal behavior. J Dev Behav Pediatr 26:77–85, 2005. Index terms: early intervention, pervasive developmental disorders, relationship focused intervention. To read the complete article please click here.
Other Relevant Publications
DIR Reader (document password: dir1315)