| Number | Name | Date | Kind |
|---|---|---|---|
| 4206119 | Harrison et al. | Jun 1980 | |
| 4206305 | Harrison et al. | Jun 1980 | |
| 4636519 | Seo et al. | Jan 1987 | |
| 4738976 | Seo et al. | Apr 1988 |
| Number | Date | Country |
|---|---|---|
| 4-68308 | Nov 1992 | JPX |
| 5271226 | Oct 1993 | JPX |
| 2263234 | Jul 1993 | GBX |
| Entry |
|---|
| Windholz et al, The Merck Index, p. 897, No. 5593 (1987). |