APA

Samuelson P. A., Nordhaus W. D., . (1989). Economics. New York: McGraw-Hill.

Chicago

Samuelson Paul Anthony, Nordhaus William D, . 1989. Economics. New York: McGraw-Hill.

Harvard

Samuelson P. A., Nordhaus W. D., . (1989). Economics. New York: McGraw-Hill.

MLA

Samuelson Paul Anthony, Nordhaus William D, . Economics. New York: McGraw-Hill. 1989.