Erhardt, R. P. (1974). The Effects of Therapeutic Exercise for Correction of Joint Limitation due to Spasticity. Fargo, ND: North Dakota State University, unpublished thesis.

Erhardt, R. P. (1990). Developmental Visual Dysfunction: Models for Assessment and Management. Maplewood, MN: Erhardt Developmental Products; translated into Japanese (1997), Tokyo, Japan: Ishiyaku Publishers.

Erhardt, R. P. (1990). The Erhardt Developmental Vision Assessment (EDVA©). Maplewood, MN: Erhardt Developmental Products.

Erhardt, R. P. (1982, 1994). Developmental Hand Dysfunction: Theory, Assessment, and Treatment (2nd ed.). Austin, TX: Pro-Ed, Inc.; translated into Japanese (1988), Tokyo, Japan: Ishiyaku Publishers.

Erhardt, R. P. (1982, 1994). The Erhardt Developmental Prehension Assessment (EDPA©). Maplewood, MN: Erhardt Developmental Products.

Erhardt, R. P. (1998). Prehension Stickers. Maplewood, MN: Erhardt Developmental Products.

Erhardt, R. P. (Ed.) (1999). Parent Articles about NDT. San Antonio: Therapy Skill Builders, a Division of the Psychological Corporation.

Erhardt, R. P. & Meade, V. (2005). Handwriting: Anatomy of a collaborative assessment/intervention model. Stillwater, MN: PDP Press.

Erhardt, R. P. (2006). The Visual-Perceptual-Motor Activities Collection. Maplewood, MN: Erhardt Developmental Products. (Original work published 1997).

Erhardt, R. P. ( 2006). The Erhardt Hand Preference Assessment (EHPA). Maplewood, MN: Erhardt Developmental Products. (Original unpublished work 1998)

Erhardt, R. P. (1992). Eye-hand coordination. In J. Case-Smith & C. Pehoski (eds.), Development of Hand Skills in the Child (pp. 13-33). Bethesda, MD: The American Occupational Therapy Association.

Erhardt, R. P. (1993). Cerebral palsy. In H. L. Hopkins & H .D. Smith (eds.), Willard & Spackman's Occupational Therapy, 8th edition (pp. 430-458). Philadelphia: J.B. Lippincott.

Erhardt, R. P. & Merrill, S. C. (1998). Neurological dysfunction in children. In M. E. Neistadt & E. B. Crepeau (eds.) Willard & Spackman's Occupational Therapy, 9th Edition. (pp. 582-607). Philadelphia: J.B. Lippincott.

Erhardt, R. P. & Lindley, S. (2000). Functional development of the hand. In A. Gupta, S. P. J. Kay & L. R. Scheker (eds.), The Growing Hand: Diagnosis and Management of the Upper Extremity in Children (pp. 71-81). London, England: Mosby.

Erhardt, R. P. & Duckman, R. H. (2005). Visual-perceptual-motor dysfunction: Effects on eye-hand coordination and skill development. In M. Gentile (Ed.), Functional visual behavior in children: An occupational therapy guide to evaluation and treatment options (2nd ed., pp. 171-229). Bethesda, MD: The American Occupational Therapy Association.

Erhardt, R. P. (1971). The occupational therapist as a school consultant for perceptual-motor programming. The American Journal of Occupational Therapy, 25(8), 411-414.

Erhardt, R. P. (1974). Sequential levels of prehension development. The American Journal of Occupational Therapy, 28(10), 592-596.

Erhardt, R. P., Beatty, P. A., & Hertsgaard, D. M. (1981). A developmental prehension assessment for handicapped children. The American Journal of Occupational Therapy, 35(4), 237-242.

Erhardt, R. P. (1985, November). NDT criteria in schools. Neuro-Developmental Treatment Association Newsletter, 6.

Erhardt, R. P. (1987). Sequential levels in the visual-motor development of a child with cerebral palsy. The American Journal of Occupational Therapy, 41(1), 43-49.

Erhardt, R. P. (1987). Visual function in the student with multiple handicaps: An integrative transdisciplinary model for assessment and intervention in home, school, and community environments. Education of the Visually Handicapped, 19(3), 87-98.

Erhardt, R. P., Beatty, P. A., & Hertsgaard, D. M. (1988). A developmental visual assessment for children with multiple handicaps. Topics in Early Childhood Special Education, 7(4), 84-101.

Erhardt, R. P. (1991-1992, Winter). Improving visual control: Activities for parents and infants. Team Talk, 1, 12-15 (available from Team Talk, P.O. Box 83165, Milwaukee, WI 53223). Reprinted in (March/April 1998) NDTA Network, 1, 3, 6.

Erhardt, R. P. & Cool, S. (1992, March). Commentaries on: Evolving methodology in disability research. NDTA Network, 6-7.

Erhardt, R. P. (1993, Fall). Finger feeding: A comprehensive developmental perspective. Pediatric Basics, 66, 2-6.

Erhardt, R. P. (1994, Fall). Utensil feeding: A comprehensive developmental perspective. Pediatric Basics, 70, 2-9.

Erhardt, R. P. (June 9, 1997). Hand Function Series #1. Hand development: Answers to some common questions. ADVANCE for Occupational Therapists, 13(23), 12.

Erhardt, R. P. (June 23, 1997). Hand Function Series #2. The prehension/vision connection: Implications for skill development. ADVANCE for Occupational Therapists, 13(25), 12.

Erhardt, R. P. (July 7, 1997). Hand Function Series #3. Early hand development: What children need for future adult performance. ADVANCE for Occupational Therapists, 13(27), 12-13.

Erhardt, R. P. (July 21, 1997). Hand Function Series #4. Therapists' hand skills: Tips for improving therapeutic handling. ADVANCE for Occupational Therapists, 13(29), 12.

Erhardt, R. P. (August, 1997). Using therapeutic touch. OT Practice, 2, 41-43.

Erhardt, R. P. (May 18, 1998). Visual Function Series #1. Visual development: Answers to some common questions. ADVANCE for Occupational Therapists, 14(20), 19-20.

Erhardt, R. P. (May 25, 1998). Visual Function Series #2. Early visual development: Preparing kids for future adult performance. ADVANCE for Occupational Therapists, 14(21), 21, 66.

Erhardt, R. P. (August 23, 1999). Feeding Function Series #1. Independent feeding: Answers to some common questions. ADVANCE for Occupational Therapists, 15(17), 31-32.

Erhardt, R. P. (September 6, 1999). Feeding Function Series #2. Failure to thrive: A sensorimotor approach. ADVANCE for Occupational Therapists, 15(18), 34-35.

Erhardt, R. P. (November 1, 1999). Feeding Function Series #3. The transition from finger feeding to utensil use. ADVANCE for Occupational Therapists, 15(22), 23-25.

Erhardt, R. P. & Meade, V. (2005). Improving handwriting without teaching handwriting: The consultative clinical reasoning process. Australian Occupational Therapy Journal, 52 (3), 199-210.

Erhardt, R. P. (April 3, 2006). Handwriting on the wall: Frequently asked questions about chalkboard activities to improve postural alignment and fine motor control. OT Practice, 11(6), 19-23.

Erhardt, R. P. (August 7, 2006). Be a Joiner: Participation in non-OT organizations. ADVANCE for Occupational Therapy Practitioners, 22(16), 20-21, 53.

Erhardt, R. P. (January 22, 2007). The right tool for the job: Creating your own assessment. ADVANCE for Occupational Therapy Practitioners, 23(2), 32-35.

Erhardt, R. P. (April 16, 2007). Circuits for success: Using the computer to organize your consulting business. ADVANCE for Occupational Therapy Practitioners, 22(16), 48-50.

Erhardt, R. P. (February 18, 2008). Office management: Strategies for your multi-faceted business. ADVANCE for Occupational Therapy Practitioners, 24(4), 52-54.

Erhardt, R. P. (March 31, 2008). Aging in place: It’s for therapists too! ADVANCE for Occupational Therapy Practitioners, 24(7), 68-70.

Erhardt, R. P. & Pullen, D. (Producers). (1981). Normal Hand Development: Birth to 15 Months [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1983). Administration of the Erhardt Developmental Prehension Assessment: The Child with Developmental Disabilities [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1985). Developmental Prehension Components of Independent Feeding: From Assessment to Treatment to Function [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1986). Normal Visual Development: Birth to 6 Months [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119).

Erhardt, R. P. (Producer). (1986). The Consultant's Role in Evaluation and Treatment of Eating Dysfunction [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1989). Administration of the Erhardt Developmental Vision Assessment [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1990). Atypical Visual-motor Function in Persons with Developmental Disabilities [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1990). Components of Visual-Motor Function in a Normal Young Adult [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1994). Administration of the Erhardt Developmental Prehension Assessment: The Adolescent with Developmental Disabilities [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1995). Development of Self-Feeding in the Normal Child [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.

Erhardt, R. P. (Producer). (1995). Self-Feeding in the Child with Special Needs [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1996). Atypical Hand Function in Persons with Disabilities [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1996). Components of Hand Function in a Normal Young Adult [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1996). Developmental Components of Eye-Hand Coordination in the Child with Special Needs [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1997). Evaluation and Treatment of the Child with Visual-Perceptual-Motor Problems: Part 1. Evaluation. Part 2. Treatment. Part 3. Re-Evaluation [videos]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (1999). Normal Components of Hand Preference [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (2000). A Sensorimotor Approach to Feeding Problems and Failure to Thrive [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)

Erhardt, R. P. (Producer). (2000). Normal and Atypical Hand Preferences [video]. (Available from Erhardt Developmental Products, 2379 Snowshoe Court, Maplewood, MN 55119.)