(Firm), P. (1997). The Guide to graduate environmental programs. Washington, D.C.
Chicago-стиль цитирования(Firm), ProQuest. The Guide to Graduate Environmental Programs. Washington, D.C, 1997.
MLA-цитирование(Firm), ProQuest. The Guide to Graduate Environmental Programs. Washington, D.C, 1997.
Предупреждение: эти цитированмия не могут быть всегда правильны на 100%.