Environmental Center of the Philippines Foundation Incorporation & Department of Environment and Natural Resources. (1991). Manual for the preparation of an area ecological profile. [s.n.].
Chicago-referens (17:e uppl.)Environmental Center of the Philippines Foundation Incorporation och Department of Environment and Natural Resources. Manual for the Preparation of an Area Ecological Profile. [s.l]: [s.n.], 1991.
MLA-referens (9:e uppl.)Environmental Center of the Philippines Foundation Incorporation och Department of Environment and Natural Resources. Manual for the Preparation of an Area Ecological Profile. [s.n.], 1991.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.