APA (7th ed.) Citation

Allerton, J. J. (2010). Once Upon A Planet. Project Gutenberg.

Chicago Style (17th ed.) Citation

Allerton, J. J. Once Upon A Planet. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Allerton, J. J. Once Upon A Planet. Project Gutenberg, 2010.

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