APA (7th ed.) Citation

Cass, S. Free as in freedom: Richard Stallman's crusade for free software [Book Review]. IEEE spectrum.

Chicago Style (17th ed.) Citation

Cass, S. "Free as in Freedom: Richard Stallman's Crusade for Free Software [Book Review]." IEEE Spectrum .

MLA (9th ed.) Citation

Cass, S. "Free as in Freedom: Richard Stallman's Crusade for Free Software [Book Review]." IEEE Spectrum, .

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