APA (7th ed.) Citation

Leinster, M. (2006). Operation: Outer Space. Project Gutenberg.

Chicago Style (17th ed.) Citation

Leinster, Murray. Operation: Outer Space. Project Gutenberg, 2006.

MLA (9th ed.) Citation

Leinster, Murray. Operation: Outer Space. Project Gutenberg, 2006.

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