APA استشهاد

Botkin, D. B., & Keller, E. A. (1982). Environmental studies. C.E. Merrill Pub. Co..

استشهاد بنمط شيكاغو

Botkin, Daniel B., و Edward A. Keller. Environmental Studies. Columbus, [Ohio]: C.E. Merrill Pub. Co., 1982.

MLA استشهاد

Botkin, Daniel B., و Edward A. Keller. Environmental Studies. C.E. Merrill Pub. Co., 1982.