Παραπομπή APA

Kohler, H. (1968). Scarcity challenged: An introduction to economics.

Παραπομπή Chicago Style

Kohler, Heinz. Scarcity Challenged: An Introduction to Economics. 1968.

Παραπομπή MLA

Kohler, Heinz. Scarcity Challenged: An Introduction to Economics. 1968.