(Firm), P. (1997). The Guide to graduate environmental programs. Washington, D.C.
Chicago-stil citat(Firm), ProQuest. The Guide to Graduate Environmental Programs. Washington, D.C, 1997.
MLA-referens(Firm), ProQuest. The Guide to Graduate Environmental Programs. Washington, D.C, 1997.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.