| Number | Date | Country | Kind |
|---|---|---|---|
| 22477/77 | May 1977 | GBX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3577420 | Hess et al. | May 1971 | |
| 3632763 | Hess et al. | Jan 1972 | |
| 4007187 | Fauran et al. | Feb 1977 |
| Entry |
|---|
| Hess et al., "Chemical Abstracts," vol. 72, 1970, col. 31834r. |
| Marquet et al., "Chemical Abstracts," vol. 72, 1970, col. 78968c. |