Cita APA (7a ed.)

Gregory, K. J. (2009). Environmental sciences: A student's companion. SAGE.

Cita Chicago Style (17a ed.)

Gregory, K. J. Environmental Sciences: A Student's Companion. Los Angeles: SAGE, 2009.

Cita MLA (8a ed.)

Gregory, K. J. Environmental Sciences: A Student's Companion. SAGE, 2009.