APA (7th ed.) Citation

Castillo, A. V. (1949). Principles of economics. University Pub. Co.

Chicago Style (17th ed.) Citation

Castillo, Andres Villegas. Principles of Economics. Manila: University Pub. Co, 1949.

MLA (9th ed.) Citation

Castillo, Andres Villegas. Principles of Economics. University Pub. Co, 1949.