Goncalves, F. E. (2010). Building telephony systems with OpenSIPS 1.6: Build scalable and robust telephony systems using SIP. Packt Pub.
Chicago-Zitierstil (17. Ausg.)Goncalves, Flavio E. Building Telephony Systems with OpenSIPS 1.6: Build Scalable and Robust Telephony Systems Using SIP. Birmingham, U.K: Packt Pub, 2010.
MLA-Zitierstil (9. Ausg.)Goncalves, Flavio E. Building Telephony Systems with OpenSIPS 1.6: Build Scalable and Robust Telephony Systems Using SIP. Packt Pub, 2010.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.