APA استشهاد

Samuelson, P. A., & Nordhaus, W. D. (1989). Economics/13e (13th ed.). Mc Graw Hill.

استشهاد بنمط شيكاغو

Samuelson, Paul A., و William D. Nordhaus. Economics/13e. 13th ed. New Delhi: Mc Graw Hill, 1989.

MLA استشهاد

Samuelson, Paul A., و William D. Nordhaus. Economics/13e. 13th ed. Mc Graw Hill, 1989.