APA (7th ed.) Citation

Tracy, L. (2010). A Mysterious Disappearance. Project Gutenberg.

Chicago Style (17th ed.) Citation

Tracy, Louis. A Mysterious Disappearance. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Tracy, Louis. A Mysterious Disappearance. Project Gutenberg, 2010.

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