APA (7e ed.) Bronvermelding

Não informado. (1961). IUCN bulletin. International Union for Conservation of Nature and Natural Resources.

Chicago (17e ed.) Bronvermelding

Não informado. IUCN Bulletin. Morges, Suíça: International Union for Conservation of Nature and Natural Resources, 1961.

MLA (8e ed.) Bronvermelding

Não informado. IUCN Bulletin. International Union for Conservation of Nature and Natural Resources, 1961.

Let op: Deze citaties zijn niet altijd 100% accuraat.