Cita APA (7th ed.)
Wilson, J. H., & Clark, J. R. (1997). Economics. National Textbook company.
Cita Chicago (17th ed.)
Wilson, J. Holton, i J. R. Clark. Economics. Cincinnati: National Textbook company, 1997.
Cita MLA (9th ed.)
Wilson, J. Holton, i J. R. Clark. Economics. National Textbook company, 1997.
Atenció: Aquestes cites poden no estar 100% correctes.