Cita APA (7a ed.)

Behrens, T. (2007). Best damn firewall book period (2nd ed.). Syngress.

Cita Chicago Style (17a ed.)

Behrens, Thorsten. Best Damn Firewall Book Period. 2nd ed. Burlington, Mass.: Syngress, 2007.

Cita MLA (8a ed.)

Behrens, Thorsten. Best Damn Firewall Book Period. 2nd ed. Syngress, 2007.