APA (7th ed.) Citation

Oppenheim, E. P. (2006). The Avenger. Project Gutenberg.

Chicago Style (17th ed.) Citation

Oppenheim, E. Phillips. The Avenger. Project Gutenberg, 2006.

MLA (9th ed.) Citation

Oppenheim, E. Phillips. The Avenger. Project Gutenberg, 2006.

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