| Number | Name | Date | Kind |
|---|---|---|---|
| 2936251 | Garceau et al. | May 1960 | |
| 3366671 | Cowen et al. | Jan 1968 | |
| 5643864 | Li et al. | Jul 1997 | |
| 5656586 | Li et al. | Aug 1997 |
| Entry |
|---|
| R. Qu et al., Riyong Huaxue Gongye May 1996, 5, 15-16 (abstract). |
| R. Qu et al. Shandong Daxue Xuebao, Ziran Kexueban Jan. 1995, 1, 100-104 (abstract). |
| M. Shi et al. Riyong Huaxue Gongye Apr. 1992, 4, 184-187 (abstract). |
| M. Shi et al., Yukagaku Jan. 1993, 42, 49-51 (abstract). |
| M. Shi et al., Chinese Chemical Letters May 1992, 3, 347-348 (abstract). |