Não informado. (1981). Abstracts on hygiene and communicable diseases. Bureau of Hygiene and Tropical Diseases.
Chicago-referens (17:e uppl.)Não informado. Abstracts on Hygiene and Communicable Diseases. London: Bureau of Hygiene and Tropical Diseases, 1981.
MLA-referens (8:e uppl.)Não informado. Abstracts on Hygiene and Communicable Diseases. Bureau of Hygiene and Tropical Diseases, 1981.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.