APA (7th ed.) Citation

Conwell, R. H. (2011). Why Lincoln Laughed. Project Gutenberg.

Chicago Style (17th ed.) Citation

Conwell, Russell H. Why Lincoln Laughed. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Conwell, Russell H. Why Lincoln Laughed. Project Gutenberg, 2011.

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