Flávio R. Avila, Andre N. Barreto. Non-intrusive speech quality estimation for GSM system using narrowband and wideband AMR codec. In Proceedings of the 2008 5th International Symposium on Wireless Communication Systems, ISWCS 2008, 21-24 October 2008, Reykjavík, Iceland. pages 173-177, IEEE, 2008. [doi]