Number | Date | Country | Kind |
---|---|---|---|
63-229480 | Sep 1988 | JPX | |
1-114676 | May 1989 | JPX |
Number | Name | Date | Kind |
---|---|---|---|
3187713 | Fenwick | Jun 1965 | |
4306294 | Hoshimoto et al. | Dec 1981 | |
4888815 | Ahlemeyer et al. | Dec 1989 |
Number | Date | Country |
---|---|---|
0068036 | Mar 1989 | JPX |
Entry |
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David M. Thomas, Radio Electronic, May 1973, pp. 42-45, 50 and 93. |