APA引文

Chopra, P. N. (2006). Principles of economics (9th ed.). Kalyani.

Chicago Edition Citation

Chopra, P. N. Principles of Economics. 9th ed. Ludhiana: Kalyani, 2006.

MLA引文

Chopra, P. N. Principles of Economics. 9th ed. Kalyani, 2006.

警告：這些引文格式不一定是100％准確.