| Number | Date | Country | Kind |
|---|---|---|---|
| 3726381 | Aug 1987 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3881015 | Black et al. | Apr 1975 | |
| 3968216 | Black et al. | Jul 1976 |
| Number | Date | Country |
|---|---|---|
| 2053175 | Jul 1971 | DEX |
| 2630847 | Jan 1978 | DEX |
| 3512084 | Oct 1986 | DEX |
| 3528214 | Feb 1987 | DEX |
| 3528215 | Feb 1987 | DEX |
| 1305547 | Feb 1973 | GBX |
| Entry |
|---|
| Chem. Abstracts 103:153321a, Durant et al. |