Number | Name | Date | Kind |
---|---|---|---|
4058672 | Crager et al. | Nov 1977 | |
4221933 | Cornell et al. | Sep 1980 | |
4357493 | Anderson et al. | Nov 1982 | |
4442502 | Friend et al. | Apr 1984 | |
4564936 | Takahashi | Jan 1986 | |
4602129 | Matthews et al. | Jul 1986 | |
4608460 | Carter et al. | Aug 1986 | |
4623761 | Winter et al. | Nov 1986 | |
4663777 | Szeto | May 1987 |
Entry |
---|
"Digital Voice Store-Forward System Answers Phones, Takes Messages", Electronics, Apr. 21, 1983. |