Lipsey, R. G. C. (1999). Principles of economics (9 edition.). Oxford University Press.
Dyfyniad Arddull ChicagoLipsey, Richard G; Chrystal. Principles of Economics. 9 edition. New York: Oxford University Press, 1999.
Dyfyniad MLALipsey, Richard G; Chrystal. Principles of Economics. 9 edition. Oxford University Press, 1999.
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