Cita APA (7th ed.)

Samuelson, P. A., & Nordhaus, W. D. (1989). Economics: Economics (13th ed.). McGraw-Hill.

Cita Chicago (17th ed.)

Samuelson, Paul A., i William D. Nordhaus. Economics: Economics. 13th ed. New York: McGraw-Hill, 1989.

Cita MLA (9th ed.)

Samuelson, Paul A., i William D. Nordhaus. Economics: Economics. 13th ed. McGraw-Hill, 1989.