Παραπομπή APA

Lipsey, R. G. (1971). An Introduction to Positive Economics (3rd ed.). English Language Book Society.

Παραπομπή Chicago Style

Lipsey, Richard G. An Introduction to Positive Economics. 3rd ed. Great Britian: English Language Book Society, 1971.

Παραπομπή MLA

Lipsey, Richard G. An Introduction to Positive Economics. 3rd ed. English Language Book Society, 1971.