APA-referens (7:e uppl.)

Alcala, A. C. (2005). The Philippines & its rich biodiversity. IN Educators speak [column]. Manila Bulletin.

Chicago-referens (17:e uppl.)

Alcala, Angel C. "The Philippines & Its Rich Biodiversity. IN Educators Speak [column]." Manila Bulletin 2005.

MLA-referens (9:e uppl.)

Alcala, Angel C. "The Philippines & Its Rich Biodiversity. IN Educators Speak [column]." Manila Bulletin, 2005.