| Number | Date | Country | Kind |
|---|---|---|---|
| 2349022 | Sep 1973 | DT |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2822381 | Dodson et al. | Feb 1958 | |
| 2860158 | Clinton | Nov 1958 | |
| 3076023 | Kaspar et al. | Jan 1963 | |
| 3492338 | Hader et al. | Jan 1970 | |
| 3939193 | Alig et al. | Feb 1976 |
| Entry |
|---|
| Chem. Abstracts, 80:37392g. |
| Chem. Abstracts, 49:6299d. |
| Chem. Abstracts, 52:11980a. |