Dyfyniad APA

Lipsey, R. G. (1963). Introduction to positive economics. English Language Book Society.

Dyfyniad Arddull Chicago

Lipsey, Richard G. Introduction to Positive Economics. London: English Language Book Society, 1963.

Dyfyniad MLA

Lipsey, Richard G. Introduction to Positive Economics. English Language Book Society, 1963.

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