APA (7th ed.) Citation

Williams, S. (2004). Free as in Freedom: Richard Stallman's Crusade for Free Software. Project Gutenberg.

Chicago Style (17th ed.) Citation

Williams, Sam. Free as in Freedom: Richard Stallman's Crusade for Free Software. Project Gutenberg, 2004.

MLA (9th ed.) Citation

Williams, Sam. Free as in Freedom: Richard Stallman's Crusade for Free Software. Project Gutenberg, 2004.

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