Sanchez, C. A. (1991). Population education (psychological, sociological, biological, anthropological) (rev. ed.). National Book Store.
Lua i Stíl Chicago (17ú heag.)Sanchez, Custodiosa A. Population Education (psychological, Sociological, Biological, Anthropological). rev. ed. Manila: National Book Store, 1991.
Lua MLA (9ú heag.)Sanchez, Custodiosa A. Population Education (psychological, Sociological, Biological, Anthropological). rev. ed. National Book Store, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.