Number | Date | Country | Kind |
---|---|---|---|
2739843 | Sep 1977 | DEX |
Number | Name | Date | Kind |
---|---|---|---|
2290294 | Riess et al. | Jul 1942 | |
2520090 | Barrett | Aug 1950 | |
4067933 | Wilson, Jr. | Jan 1978 |
Entry |
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Chemical Abstracts, Abstract of Japanese Kokai 74,118,914, Nov. 13, 1974. |