APA-referens (7:e uppl.)

Pena, A. D. (1972). An analysis of the distribution of GIA projects 1966-70.

Chicago-referens (17:e uppl.)

Pena, Alberto D. An Analysis of the Distribution of GIA Projects 1966-70. Quezon City, 1972.

MLA-referens (9:e uppl.)

Pena, Alberto D. An Analysis of the Distribution of GIA Projects 1966-70. 1972.