APA استشهاد

Welfling, W., & Vaish, M. C. Principles of economics.

استشهاد بنمط شيكاغو

Welfling, Weldon, و M. C. Vaish. Principles of Economics. :.

MLA استشهاد

Welfling, Weldon, و M. C. Vaish. Principles of Economics.