APA (7th ed.) Citation

Zwicky, Cooper, & Chapman. (2000). Building Internet firewalls (2nd ed.). O'Reilly.

Chicago Style (17th ed.) Citation

Zwicky, Cooper, and Chapman. Building Internet Firewalls. 2nd ed. Sebastopol, Calif: O'Reilly, 2000.

MLA (8th ed.) Citation

Zwicky, et al. Building Internet Firewalls. 2nd ed. O'Reilly, 2000.