| Number | Date | Country | Kind |
|---|---|---|---|
| 9313365 | Jun 1993 | GBX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5240960 | Hambleton et al. | Aug 1993 | |
| 5308865 | Bartlett et al. | May 1994 | |
| 5312830 | Kuo | May 1994 |
| Number | Date | Country |
|---|---|---|
| 0551230 | Jul 1993 | FRX |
| 2524929 | Jan 1980 | DEX |
| PCTEP9001800 | Oct 1990 | WOX |
| Entry |
|---|
| Axton, et. al., Chem. Soc. Perkin. Trans. 1(1992), pp. 2203-2213. |