Number | Date | Country | Kind |
---|---|---|---|
61-301360 | Dec 1986 | JPX |
Number | Name | Date | Kind |
---|---|---|---|
2673277 | Lemmens et al. | Mar 1954 | |
4570099 | Green | Feb 1986 |
Entry |
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Reinhold Publishing Company, (1960), pp. 538-541, "Materials and Techniques For Electron Tubes"; Walter H. Kohl. |