APA (7th ed.) Citation

Allen, W. B. (2013). The Violet Book. Project Gutenberg.

Chicago Style (17th ed.) Citation

Allen, Willis Boyd. The Violet Book. Project Gutenberg, 2013.

MLA (9th ed.) Citation

Allen, Willis Boyd. The Violet Book. Project Gutenberg, 2013.

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