Gaya APA

Samuelson, P, A., Samuelson, W. (1980). Economics / Paul A. Samuelson, William Samuelson (Ed.ke-7). : McGraw-Hill International Book Company.

Gaya MLA

Samuelson, Paul, A.., Samuelson, William. "Economics / Paul A. Samuelson, William Samuelson". Ed.ke-7 : McGraw-Hill International Book Company, 1980. Textbook.