APA (7th ed.) Citation

Zimmermann, P. (1995). PGP source code and internals. MIT Press.

Chicago Style (17th ed.) Citation

Zimmermann, Philip. PGP Source Code and Internals. Cambridge, Mass. u.a: MIT Press, 1995.

MLA (9th ed.) Citation

Zimmermann, Philip. PGP Source Code and Internals. MIT Press, 1995.