Cita APA (7a ed.)
Gregory, P. R. (1990). Essentials of economics (2nd ed.). Scott, Foresman.
Cita Chicago Style (17a ed.)
Gregory, Paul R. Essentials of Economics. 2nd ed. Glenview, Ill.: Scott, Foresman, 1990.
Cita MLA (9a ed.)
Gregory, Paul R. Essentials of Economics. 2nd ed. Scott, Foresman, 1990.
Precaución: Estas citas no son 100% exactas.