Number | Name | Date | Kind |
---|---|---|---|
3348210 | Ochsner | Oct 1967 | |
3781818 | Pardoe et al. | Dec 1973 | |
3787818 | Arnold et al. | Jan 1974 | |
3856993 | Closs et al. | Dec 1974 | |
3934232 | Curley et al. | Jan 1976 | |
3943494 | Holmes, Jr. et al. | Mar 1976 | |
3959775 | Valassis et al. | May 1976 | |
3969701 | Hemdal | Jul 1976 | |
3970994 | Jenny | Jul 1976 | |
3978455 | Valassis et al. | Aug 1976 | |
3984819 | Anderson | Oct 1976 | |
3997896 | Cassarino, Jr. et al. | Dec 1976 | |
4023145 | Duerdoth et al. | May 1977 | |
4025725 | Euler | May 1977 | |
4030072 | Bjornsson | Jun 1977 | |
4031512 | Faber | Jun 1977 | |
4045617 | Schlichte | Aug 1977 | |
4074072 | Christensen et al. | Feb 1978 | |
4113988 | Mukaemachi et al. | Sep 1978 | |
4146749 | Pepping et al. | Mar 1979 |
Number | Date | Country |
---|---|---|
2502516 | Jul 1975 | DEX |
1214106 | Dec 1970 | GBX |
Entry |
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"Study of a Rural Digital End Office," by Michael J. Kelly, Telephone Engineer & Management, Dec. 1, 1977. |