Cita APA (7th ed.)

Heilbroner, R. L. (1981). The economic problem (6th ed.). Prentice-Hall.

Cita Chicago (17th ed.)

Heilbroner, Robert L. The Economic Problem. 6th ed. Englewood Cliffs, N.J: Prentice-Hall, 1981.

Cita MLA (9th ed.)

Heilbroner, Robert L. The Economic Problem. 6th ed. Prentice-Hall, 1981.