APA (7th ed.) Citation

Holmes, T. (1998). London's Underworld. Project Gutenberg.

Chicago Style (17th ed.) Citation

Holmes, Thomas. London's Underworld. Project Gutenberg, 1998.

MLA (9th ed.) Citation

Holmes, Thomas. London's Underworld. Project Gutenberg, 1998.

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