APA (7th ed.) Citation

Twain, M. (1997). A Horse's Tale. Project Gutenberg.

Chicago Style (17th ed.) Citation

Twain, Mark. A Horse's Tale. Project Gutenberg, 1997.

MLA (9th ed.) Citation

Twain, Mark. A Horse's Tale. Project Gutenberg, 1997.

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