APA (7th ed.) Citation

Ricardo, D. (2010). On The Principles of Political Economy, and Taxation. Project Gutenberg.

Chicago Style (17th ed.) Citation

Ricardo, David. On The Principles of Political Economy, and Taxation. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Ricardo, David. On The Principles of Political Economy, and Taxation. Project Gutenberg, 2010.

Warning: These citations may not always be 100% accurate.