APA (7e ed.) Bronvermelding

Elec, B. M., Lerios, M. C., Belarmino, M. C., & Velasquez, G. A. (1999). Personalized system of instruction (PSI) for college algebra. Learning Resource Center, University of the Philippines.

Chicago (17e ed.) Bronvermelding

Elec, Bernarda M., Marcelina C. Lerios, Myrna C. Belarmino, en Gemma A. Velasquez. Personalized System of Instruction (PSI) for College Algebra. Quezon City: Learning Resource Center, University of the Philippines, 1999.

MLA (9e ed.) Bronvermelding

Elec, Bernarda M., et al. Personalized System of Instruction (PSI) for College Algebra. Learning Resource Center, University of the Philippines, 1999.