Cita APA (7th ed.)

Villegas, B. M., & Abola, V. A. (1982). Economics: An introduction. Sinag-Tala Pub.

Cita Chicago (17th ed.)

Villegas, Bernardo M., i Victor A. Abola. Economics: An Introduction. Manila: Sinag-Tala Pub, 1982.

Cita MLA (9th ed.)

Villegas, Bernardo M., i Victor A. Abola. Economics: An Introduction. Sinag-Tala Pub, 1982.