Number | Date | Country | Kind |
---|---|---|---|
3108177 | Mar 1981 | DEX |
Number | Date | Country |
---|---|---|
2034186 | Jan 1971 | DEX |
Entry |
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Optics Communications, vol. 29, No. 2, May 1979 at 239. |
Optics Communications, vol. 23, No. 3, Dec. 1977 at 293. |
Optics Communications, vol. 30, No. 3, Sep. 1979 at 453. |