APA (7th ed.) Citation

Ferris, B., & Napoli, V. (2007). The Invaders. Project Gutenberg.

Chicago Style (17th ed.) Citation

Ferris, Benjamin, and Vincent Napoli. The Invaders. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Ferris, Benjamin, and Vincent Napoli. The Invaders. Project Gutenberg, 2007.

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