Gaya APA

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

Gaya MLA

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