Robar, A. (2009). FreePBX 2.5 powerful telephony solutions: Configure, deploy, and maintain an enterprise-class VoIP PBX. Packt Publishing.
Chicago Style (17th ed.) CitationRobar, Alex. FreePBX 2.5 Powerful Telephony Solutions: Configure, Deploy, and Maintain an Enterprise-class VoIP PBX. Birmingham, UK: Packt Publishing, 2009.
MLA (9th ed.) CitationRobar, Alex. FreePBX 2.5 Powerful Telephony Solutions: Configure, Deploy, and Maintain an Enterprise-class VoIP PBX. Packt Publishing, 2009.
Warning: These citations may not always be 100% accurate.