Environmental Careers Organization & ebrary, Inc. (2004). The ECO guide to careers that make a difference. Island Press.
Chicago-referens (17:e uppl.)Environmental Careers Organization och Inc ebrary. The ECO Guide to Careers That Make a Difference. Washington: Island Press, 2004.
MLA-referens (9:e uppl.)Environmental Careers Organization och Inc ebrary. The ECO Guide to Careers That Make a Difference. Island Press, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.