Cita APA (7th ed.)

Robar, A. (2009). FreePBX 2.5 powerful telephony solutions: Configure, deploy, and maintain an enterprise-class VoIP PBX. Packt Publishing.

Cita Chicago (17th ed.)

Robar, Alex. FreePBX 2.5 Powerful Telephony Solutions: Configure, Deploy, and Maintain an Enterprise-class VoIP PBX. Birmingham, UK: Packt Publishing, 2009.

Cita MLA (9th ed.)

Robar, Alex. FreePBX 2.5 Powerful Telephony Solutions: Configure, Deploy, and Maintain an Enterprise-class VoIP PBX. Packt Publishing, 2009.