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AT & T Technology, vol. 4, No. 2, 1989, Short Hills, N.J. US, XP86281 M. R. Croak "Unified Messaging Will Deliver The Message". |
Review of the Electrical Communications Laboratories, vol. 1, 35, No. 6, Nov. 1987, Tokyo Japan, pp. 613-612, Kawanaka et al "Voice Mail System". |
International Switching Symposium 1990, vol. 1, May 1990, Stockholm, Sweden pp. 137-142, XP130833, Berger et al, "AT&T VoiceMark Messaging Service-A New Voice Store and Forward Service". |