APA (7e ed.) Bronvermelding

Hannaford, J., & Heilbroner, R. L. (1972). A programmed guide to The economic problem, third edition [by] Robert L. Heilbroner. Prentice-Hall.

Chicago (17e ed.) Bronvermelding

Hannaford, John, en Robert L. Heilbroner. A Programmed Guide to The Economic Problem, Third Edition [by] Robert L. Heilbroner. Englewood Cliffs, N.J.: Prentice-Hall, 1972.

MLA (8e ed.) Bronvermelding

Hannaford, John, en Robert L. Heilbroner. A Programmed Guide to The Economic Problem, Third Edition [by] Robert L. Heilbroner. Prentice-Hall, 1972.