APA (7th ed.) Citation

Sheldon, W. J. (2009). Two Plus Two Makes Crazy. Project Gutenberg.

Chicago Style (17th ed.) Citation

Sheldon, Walter J. Two Plus Two Makes Crazy. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Sheldon, Walter J. Two Plus Two Makes Crazy. Project Gutenberg, 2009.

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