IEEE (2002). "QoS classification for mobile networks: International roaming case study". 5th IEEE International Conference on High Speed Networks and Multimedia Communications, HSNMC 2002 : July 3 - 5, 2002, Jeju Island, Korea. Piscataway, NJ: IEEE Operations Center. pp. 356–360. doi:10.1109/HSNMC.2002.1032607. ISBN978-0-7803-7600-7. S2CID61454234.
Beccaris, R.; Albacar, X.P.; Proulx, M.; Settimo, F. (1998). "Signalling interoperability as a key enabler to GSM/PCS roaming with North America". VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151). Vol. 1. IEEE Xplore. pp. 122–126. doi:10.1109/VETEC.1998.686490. ISBN978-0-7803-4320-7. S2CID61666579.
IEEE (2002). "QoS classification for mobile networks: International roaming case study". 5th IEEE International Conference on High Speed Networks and Multimedia Communications, HSNMC 2002 : July 3 - 5, 2002, Jeju Island, Korea. Piscataway, NJ: IEEE Operations Center. pp. 356–360. doi:10.1109/HSNMC.2002.1032607. ISBN978-0-7803-7600-7. S2CID61454234.
Beccaris, R.; Albacar, X.P.; Proulx, M.; Settimo, F. (1998). "Signalling interoperability as a key enabler to GSM/PCS roaming with North America". VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151). Vol. 1. IEEE Xplore. pp. 122–126. doi:10.1109/VETEC.1998.686490. ISBN978-0-7803-4320-7. S2CID61666579.