Cita APA (7a ed.)

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.

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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