Cita APA

Discovery Channel School, Entrex Software, QuickTime, & World Book. (2004). Ecology [computer file]. Discovery Communications, Inc.

Citación estilo Chicago

Discovery Channel School, Entrex Software, QuickTime, and World Book. Ecology [computer File]. [U.S.A.]: Discovery Communications, Inc, 2004.

Cita MLA

Discovery Channel School, et al. Ecology [computer File]. Discovery Communications, Inc, 2004.