1. Sexual activity and contraceptive practice among teenagers in the United States, 1988 and 1995 (DHHS Publication No.2001-1997);Abma,2001
2. Manual for the Child Behavior Checklist/4-18 and the 1991 profile;Achenbach,1991
3. Female homosexual behavior in Macacca mulatto;Akers;Archives of Sexual Behavior,1979
4. Biological Exuberance: Animal Homosexuality and Natural Diversity;Bagemihl,1999
5. Genetics of human sexual orientation;Bailey;Annual Review of Sex Research,1995