APA (7th ed.) Citation

Hitchcock, E., & Whewell, W. (2011). The Plurality of Worlds. Project Gutenberg.

Chicago Style (17th ed.) Citation

Hitchcock, Edward, and William Whewell. The Plurality of Worlds. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Hitchcock, Edward, and William Whewell. The Plurality of Worlds. Project Gutenberg, 2011.

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