| Number | Date | Country | Kind |
|---|---|---|---|
| 29651/74 | Jul 1974 | UK |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2245147 | John et al. | Jun 1941 | |
| 3420853 | Moed et al. | Jan 1969 | |
| 3458565 | Bicking et al. | Jul 1969 | |
| 3646114 | Pitt | Feb 1972 | |
| 3879449 | Anderson et al. | Apr 1975 |
| Number | Date | Country |
|---|---|---|
| 1,582,621 | Oct 1969 | FR |
| Entry |
|---|
| Johnson et al., J. Chem. & Eng. Data, vol. 16, No. 1, pp. 112-115 (1971). |
| Sylvestre; Julia et al., C. R. Acad. Sc. Paris, Series C, t270 pp. 1308-1311 (1970). |