APA-referens (7:e uppl.)
Environmental Law Institute & ebrary, Inc. (1999). Protecting Delaware's natural heritage: Tools for biodiversity conservation. Environmental Law Institute.
Chicago-referens (17:e uppl.)
Environmental Law Institute och Inc ebrary. Protecting Delaware's Natural Heritage: Tools for Biodiversity Conservation. Washington, D.C.: Environmental Law Institute, 1999.
MLA-referens (9:e uppl.)
Environmental Law Institute och Inc ebrary. Protecting Delaware's Natural Heritage: Tools for Biodiversity Conservation. Environmental Law Institute, 1999.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.