APA

Castillo I., U.S. Fish and Wildlife Service, U.S. National Park Service & World Wildlife Fund. (1991). Presentaciones selectas de la 19ava. Washington: The North American Association for Environmental Education.

Chicago

Castillo Isabel, U.S. Fish and Wildlife Service, U.S. National Park Service and World Wildlife Fund. 1991. Presentaciones selectas de la 19ava. Washington: The North American Association for Environmental Education.

Harvard

Castillo I., U.S. Fish and Wildlife Service, U.S. National Park Service and World Wildlife Fund. (1991). Presentaciones selectas de la 19ava. Washington: The North American Association for Environmental Education.

MLA

Castillo Isabel, U.S. Fish and Wildlife Service, U.S. National Park Service and World Wildlife Fund. Presentaciones selectas de la 19ava. Washington: The North American Association for Environmental Education. 1991.