Number | Date | Country | Kind |
---|---|---|---|
3403345 | Feb 1984 | DEX |
Number | Name | Date | Kind |
---|---|---|---|
2493170 | Stiff et al. | Jan 1950 | |
3694578 | Reid | Sep 1970 | |
3915100 | Sullivan | Oct 1975 | |
4163867 | Breidenbach | Jun 1977 | |
4400724 | Fields | Jun 1981 | |
4511198 | Mitchell et al. | Apr 1985 |
Number | Date | Country |
---|---|---|
1980884 | Mar 1968 | DEX |
2009596 | Sep 1970 | DEX |
2525498 | Dec 1976 | DEX |
Entry |
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"A Communication System for Remote Conference", Trueman, Systems Technology, Jun. 1976, No. 24, pp. 17-21. |