APA (7e ed.) Bronvermelding

Trio, J. K., Valencia, C., Manacsa, R., & Flor, R. (1990). Friendly grocer: Amidst tough competition. UP College of Engineering.

Chicago (17e ed.) Bronvermelding

Trio, John Kenneth, Carlos Valencia, Roberto Manacsa, en Roger Flor. Friendly Grocer: Amidst Tough Competition. Quezon City: UP College of Engineering, 1990.

MLA (9e ed.) Bronvermelding

Trio, John Kenneth, et al. Friendly Grocer: Amidst Tough Competition. UP College of Engineering, 1990.