APA (7th ed.) Citation

Twain, M. (2005). Roughing It. Project Gutenberg.

Chicago Style (17th ed.) Citation

Twain, Mark. Roughing It. Project Gutenberg, 2005.

MLA (9th ed.) Citation

Twain, Mark. Roughing It. Project Gutenberg, 2005.

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