Cita APA (7th ed.)

Melvin, M. &. B. (2013). Principles of Economics (9th.). Cengage Learning.

Cita Chicago (17th ed.)

Melvin, Michael & Boyes. Principles of Economics. 9th. Canada: Cengage Learning, 2013.

Cita MLA (9th ed.)

Melvin, Michael & Boyes. Principles of Economics. 9th. Cengage Learning, 2013.