Sharp, A. M., Register, C. A., & Grimes, P. W. (2013). Economics of social issues (Twentieth edition.). McGraw-Hill.
Cita Chicago (17th ed.)Sharp, Ansel Miree, Charles A. Register, i Paul W. Grimes. Economics of Social Issues. Twentieth edition. New York: McGraw-Hill, 2013.
Cita MLA (9th ed.)Sharp, Ansel Miree, et al. Economics of Social Issues. Twentieth edition. McGraw-Hill, 2013.
Atenció: Aquestes cites poden no estar 100% correctes.