Lipsey, R. G. (1999). Principles of economics (9th ed.). Univ. Pr.
Cita Chicago (17th ed.)Lipsey, Richard G. Principles of Economics. 9th ed. Oxford: Univ. Pr, 1999.
Cita MLA (9th ed.)Lipsey, Richard G. Principles of Economics. 9th ed. Univ. Pr, 1999.
Atenció: Aquestes cites poden no estar 100% correctes.