APA

International Union for Conservation of Nature and Natural Resources, . (1971). Occasional paper / International Union for Conservation of Nature and Natural Resources, IUCN. Morges: IUCN.

Chicago

International Union for Conservation of Nature and Natural Resources, . 1971. Occasional paper / International Union for Conservation of Nature and Natural Resources, IUCN. Morges: IUCN.

Harvard

International Union for Conservation of Nature and Natural Resources, . (1971). Occasional paper / International Union for Conservation of Nature and Natural Resources, IUCN. Morges: IUCN.

MLA

International Union for Conservation of Nature and Natural Resources, . Occasional paper / International Union for Conservation of Nature and Natural Resources, IUCN. Morges: IUCN. 1971.