Gaya APA

Heilbroner, R, L. (1990). The Economic problem 9th (9th ed.). Englewood Cliffs, NJ: Prentice-Hall, c.

Gaya MLA

Heilbroner, Robert, L.. "The Economic problem 9th". 9th ed. Englewood Cliffs, NJ: Prentice-Hall, c, 1990. Buku Umum.