APA (7th ed.) Citation

Twain, M., & Warner, C. D. (2005). The Gilded Age. Project Gutenberg.

Chicago Style (17th ed.) Citation

Twain, Mark, and Charles Dudley Warner. The Gilded Age. Project Gutenberg, 2005.

MLA (9th ed.) Citation

Twain, Mark, and Charles Dudley Warner. The Gilded Age. Project Gutenberg, 2005.

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