| Number | Name | Date | Kind |
|---|---|---|---|
| 2009063 | Laska et al. | Jul 1935 | |
| 2080191 | Straub et al. | May 1937 | |
| 2150772 | Lange | Mar 1939 | |
| 3037014 | Liechti | May 1962 | |
| 3350384 | Conway | Oct 1967 | |
| 3476500 | Litke | Nov 1969 |
| Number | Date | Country |
|---|---|---|
| 0012297 | Jun 1980 | EPX |
| 1619319 | Oct 1969 | DEX |
| 2018937 | Nov 1970 | DEX |
| 1309903 | Mar 1973 | GBX |
| Entry |
|---|
| Bykov et al., Chemical Abstracts, vol. 59, #4067f,g, (1963). |