Number | Name | Date | Kind |
---|---|---|---|
1958295 | Christensen et al. | May 1934 | |
2257899 | Britton et al. | Oct 1941 | |
3669676 | Karr et al. | Jun 1972 | |
3934037 | Lewis et al. | Jan 1976 |
Entry |
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Rose et al., "The Condensed Chemical Dictionary" Van Nostrand Reinhold Co., 1970, pp. 241 and 420. |