Population Center Foundation. Population Data Information Service. (1977). Catalogue of research abstracts, number two. Population Information Division.
Chicago-referens (17:e uppl.)Population Center Foundation. Population Data Information Service. Catalogue of Research Abstracts, Number Two. Manila: Population Information Division, 1977.
MLA-referens (9:e uppl.)Population Center Foundation. Population Data Information Service. Catalogue of Research Abstracts, Number Two. Population Information Division, 1977.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.