APA (7th ed.) Citation

Gilbert, R. E., & Terry, W. E. (2009). Stopover Planet. Project Gutenberg.

Chicago Style (17th ed.) Citation

Gilbert, Robert E., and W. E. Terry. Stopover Planet. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Gilbert, Robert E., and W. E. Terry. Stopover Planet. Project Gutenberg, 2009.

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