Edwards, S. D. (2012). Treatment of autism and attachment with Interpersonal Equine Therapy (IPET). In K. Trotter (Ed.), Harness the Power of Equine Assisted Counseling: Adding Animal Assisted Therapy to Your Practice. New York: Routledge.
***Available on Amazon.com and directly from the Publisher***

Edwards, S. (1982). Social potential expressed in captive, group living orang-utans. In L.E.M. de Boer (Ed.), The Orang-utan:  Its Biology and Conservation. New York: Springer Publishing.

Edwards, S., & Snowdon, C. (1980). Social behavior of captive, group-living orang-utans. International Journal of Primatology, 1(1), 39-62.