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2. Danielson, F. H., & Davenport, C. D. (1912). The hill folk. Cold Spring Harbor, NY: Knopf.
3. Dugdale, R. L. (1910). The Jukes. (4th ed.) New York: Putman.
4. Education for all Handicapped Children Act of 1975, P.L. 94-142 (1977, December), Federal Register, p. 65083,121a.5.
5. Goddard, H. H. (1914). The Kallikak family: A study of the heredity offeeble-mindedness. New York: Macmillian.