Cita APA (7th ed.)

Rivero, G. O. C., & Cao, E. P. (2005). Biology: A study guide (2nd ed.). University of the Philippines Open University.

Cita Chicago (17th ed.)

Rivero, Gilda O. Carballo, i Ernelea Palo Cao. Biology: A Study Guide. 2nd ed. Quezon City: University of the Philippines Open University, 2005.

Cita MLA (9th ed.)

Rivero, Gilda O. Carballo, i Ernelea Palo Cao. Biology: A Study Guide. 2nd ed. University of the Philippines Open University, 2005.