Cita APA (7th ed.)

Villanueva, P. M. (1989). English skills for college freshmen. Katha Pub.

Cita Chicago (17th ed.)

Villanueva, Perla M. English Skills for College Freshmen. Quezon City: Katha Pub, 1989.

Cita MLA (9th ed.)

Villanueva, Perla M. English Skills for College Freshmen. Katha Pub, 1989.