| Number | Date | Country | Kind | 
|---|---|---|---|
| 5-017695 | Feb 1993 | JPX | |
| 5-027974 | Feb 1993 | JPX | 
| Number | Name | Date | Kind | 
|---|---|---|---|
| 5112959 | Miyamoto et al. | May 1992 | |
| 5138041 | Buch et al. | Aug 1992 | |
| 5243034 | Tappe et al. | Sep 1993 | 
| Number | Date | Country | 
|---|---|---|
| 0266774A1 | May 1988 | EPX | 
| 0374758A1 | Jun 1990 | EPX | 
| 0400648A1 | Dec 1990 | EPX | 
| 0489692 | Jun 1992 | EPX | 
| 0499588 | Aug 1992 | EPX | 
| 0535644 | Apr 1993 | EPX | 
| Entry | 
|---|
| Washimi et al, Chemical Abstracts, 117: 152728r (1992). |