Gaya APA

Nordhaus, W, D., Samuelson, P, A. (1989). Economics / Paul A. Samuelson, William D. Nordhaus (Ed.ke-13). New York: McGraw-Hill book company.

Gaya MLA

Nordhaus, William, D.., Samuelson, Paul, A.. "Economics / Paul A. Samuelson, William D. Nordhaus". Ed.ke-13 New York: McGraw-Hill book company, 1989. Textbook.