APA (7th ed.) Citation

Gerard, J. (2010). The Old Riddle and the Newest Answer. Project Gutenberg.

Chicago Style (17th ed.) Citation

Gerard, John. The Old Riddle and the Newest Answer. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Gerard, John. The Old Riddle and the Newest Answer. Project Gutenberg, 2010.

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