| Number | Date | Country | Kind |
|---|---|---|---|
| 42 42 970.6 | Dec 1992 | DEX | |
| 43 20 733.2 | Jun 1993 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4210593 | Halmos | Jul 1980 | |
| 4350632 | Springer | Sep 1982 | |
| 4394129 | Springer | Jul 1983 |
| Number | Date | Country |
|---|---|---|
| 57-199878 | Dec 1982 | JPX |
| 2246352 | Jan 1992 | GBX |
| Entry |
|---|
| Journal of the American Chemical Society, Bd. 82, Nr. 5, Mar. 16, 1960. |
| Chemical Abstracts, vol. 55, No. 16, Aug. 7, 1961, Abstract No. 16563i. |
| Gazzetta Chimica Italiana, Bd. 90, 1960, Turin Italy, pp. 841-847. |