found: Play as a learning medium, c1974.
found: Her Your child and Play, 1981:t.p. (Doris Bergen Sponseller; Ph. D.; U.S. Dept. of Health and Human Services, Head Start Bureau) [info. from GPO]
found: Play as a medium for learning and development, c1987:CIP t.p. (Doris Bergen; Dept. of Psychology and Counseling, Pittsburg State Univ.)
found: Phone call to publisher, 11/14/86(author now using name: Doris Bergen)
found: Assessment methods for infants and toddlers, c1994:CIP t.p. (Doris Bergen) data sheet (b. 2/11/32)