APA (7e ed.) Bronvermelding

Amacher, R. C. (1989). Principles of economics / Ryan C. Amacher, Hally H. Ulrich (4th ed.). South-Western Pub.

Chicago (17e ed.) Bronvermelding

Amacher, Ryan C. Principles of Economics / Ryan C. Amacher, Hally H. Ulrich. 4th ed. Cincinnati, Ohio: South-Western Pub, 1989.

MLA (9e ed.) Bronvermelding

Amacher, Ryan C. Principles of Economics / Ryan C. Amacher, Hally H. Ulrich. 4th ed. South-Western Pub, 1989.