APA (7th ed.) Citation

Zimmermann, P. (1996). The official PGP userʹs guide. MIT.

Chicago Style (17th ed.) Citation

Zimmermann, Philip. The Official PGP Userʹs Guide. Cambridge, Mass.: MIT, 1996.

MLA (8th ed.) Citation

Zimmermann, Philip. The Official PGP Userʹs Guide. MIT, 1996.

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