APA (7th ed.) Citation

Chesterton, G. K. (2007). The Man Who was Thursday, A Nightmare. Project Gutenberg.

Chicago Style (17th ed.) Citation

Chesterton, G. K. The Man Who Was Thursday, A Nightmare. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Chesterton, G. K. The Man Who Was Thursday, A Nightmare. Project Gutenberg, 2007.

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