| Number | Date | Country | Kind |
|---|---|---|---|
| 3341/80 | Apr 1980 | CHX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2200543 | Dickey et al. | May 1940 | |
| 2286795 | Dickey et al. | Jun 1942 | |
| 2328570 | McNally et al. | Sep 1943 | |
| 2638478 | Morrison et al. | May 1953 |
| Entry |
|---|
| Cook et al., Chemical Abstracts, vol. 44, 3877 to 3878, (1950). |