Gaya APA

Sampson, R, J., Marienhoff, I. (1983). The American Economy: Analysis Issues Principles . U.S.A: Houghton Mifflin Company.

Gaya MLA

Sampson, Roy, J.., Marienhoff, Ira. "The American Economy: Analysis Issues Principles". U.S.A: Houghton Mifflin Company, 1983. Book.