| Number | Date | Country | Kind |
|---|---|---|---|
| 3739349 | Nov 1987 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4504273 | Begrich et al. | Mar 1985 | |
| 4585460 | Schwander et al. | Apr 1986 | |
| 4644058 | Shimidzu et al. | Feb 1987 | |
| 4659807 | Segal | Apr 1987 |
| Number | Date | Country |
|---|---|---|
| 0078024 | Sep 1984 | EPX |
| 0181585 | May 1986 | EPX |
| 1271226 | Apr 1972 | GBX |
| 2010882 | Mar 1982 | GBX |
| Entry |
|---|
| Tilak et al., Chemistry and Industry (London), 29-31, (1981). |