Gaya APA

Samuelson, P, A., Nordhaus, W, D. (1985). Economics (Weeding) (12th ed.). New York: McGraw-Hill Book Company.

Gaya MLA

Samuelson, Paul, A.., Nordhaus, William, D.. "Economics (Weeding)". 12th ed. New York: McGraw-Hill Book Company, 1985. Text.