Coba jelasin Pustaka dari Global System for Mobile Communications dong

Siegmund M. Redl, Matthias K. Weber, Malcolm W. Oliphant: "An Introduction to GSM", Artech House, March 1995, ISBN 13:978-0890067857

Siegmund M. Redl, Matthias K. Weber, Malcolm W. Oliphant: "GSM and Personal Communications Handbook", Artech House, May 1998, ISBN 13: 978-0890069578

Yuliarso, Eddy: "Majalah Insinyur Indonesia", No. 23 Thn XV