APA (7th ed.) Citation

Phillips, R., & Terry, W. E. (2008). Unthinkable. Project Gutenberg.

Chicago Style (17th ed.) Citation

Phillips, Rog, and W. E. Terry. Unthinkable. Project Gutenberg, 2008.

MLA (9th ed.) Citation

Phillips, Rog, and W. E. Terry. Unthinkable. Project Gutenberg, 2008.

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