Citação norma APA

Educational Facilities Laboratories, National Education Association of the United States, United States. National Park Service, & Ezersky, E. (1972). Environmental education. S.n.

Citação norma Chicago

Educational Facilities Laboratories, National Education Association of the United States, United States. National Park Service, and Eugene Ezersky. Environmental Education. New York: S.n, 1972.

Citação norma MLA

Educational Facilities Laboratories, et al. Environmental Education. S.n, 1972.

Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.