Rogerson, D., Grunfeld, H. Number Portability. London: Ovum Ltd., 1996 337 p. il. 1 898972 36 2.
Rogerson, D., Grunfeld, H. Number Portability. London: Ovum Ltd., 1996 337 p. il. 1 898972 36 2.
Rogerson, D., Grunfeld, H. (1996) Number Portability, London: Ovum Ltd. 337 p. il. 1 898972 36 2.
Rogerson, D., & Grunfeld, H. (1996). Number Portability. Strategies for market, technical and regulatory success. London: Ovum Ltd., 337 p. il.
Rogerson D, Grunfeld H. Number Portability: Strategies for market, technical and regulatory success. London: Ovum Ltd.; 1996. p. 337 p. il. ISBN: 1 898972 36 2.