| Number | Name | Date | Kind |
|---|---|---|---|
| D214795 | Bearse | Jul 1969 | |
| D216428 | Bearse | Jan 1970 | |
| D219589 | Miller | Dec 1970 | |
| D220218 | Jacobs et al. | Mar 1971 | |
| D220698 | Kapper | May 1971 | |
| D223252 | Jacobson | Apr 1972 | |
| D225858 | Klene | Jan 1973 | |
| D232563 | Marchese | Aug 1974 | |
| D242930 | Jackson et al. | Jan 1977 | |
| D254436 | Bakal | Mar 1980 | |
| D260883 | Hasted | Sep 1981 | |
| D264348 | Turk et al. | May 1982 | |
| D272433 | Trabacchi et al. | Jan 1984 | |
| D273954 | Bee | May 1984 | |
| 4056699 | Jordan | Nov 1977 | |
| 4065649 | Carter et al. | Dec 1977 | |
| 4066850 | Heyes | Jan 1978 | |
| 4291198 | Anderson et al. | Sep 1981 | |
| 4303811 | Parkinson | Dec 1981 | |
| 4317011 | Mazark | Feb 1982 | |
| 4341929 | Alexander et al. | Jul 1982 | |
| 4385212 | Tyler | Mar 1983 |
| Entry |
|---|
| Hungarian Machinery, 4th Quarter 1980, vol. 31, #4; Article on "Budavox Party Line . . . Phone Systems"; pp. 22-29. |
| Report on Int'l Conference on Private Electronic Switching Systems, London, England; 4-1978; Authors Griffiths & Card; pp. 54-59. |
| Hasler Review, vol. 11, #2/3 (Autum 1978); Article by Schibi, pp. 57-60. |