APA (7th ed.) Citation

Machen, A. (2011). The Terror A Mystery. Project Gutenberg.

Chicago Style (17th ed.) Citation

Machen, Arthur. The Terror A Mystery. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Machen, Arthur. The Terror A Mystery. Project Gutenberg, 2011.

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