Philippines. Department of Education, Culture and Sports, & Philippines. Environmenment Management Bureau. (1999). Environmental education guide. DECS].
Chicago-referens (17:e uppl.)Philippines. Department of Education, Culture and Sports, och Philippines. Environmenment Management Bureau. Environmental Education Guide. [Pasig City: DECS], 1999.
MLA-referens (9:e uppl.)Philippines. Department of Education, Culture and Sports, och Philippines. Environmenment Management Bureau. Environmental Education Guide. DECS], 1999.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.