APA (7th ed.) Citation

Garfinkel, S. (1995). PGP: Pretty good privacy. O'Reilly.

Chicago Style (17th ed.) Citation

Garfinkel, Simson. PGP: Pretty Good Privacy. Sebastopol, CA: O'Reilly, 1995.

MLA (9th ed.) Citation

Garfinkel, Simson. PGP: Pretty Good Privacy. O'Reilly, 1995.

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