Number | Date | Country | Kind |
---|---|---|---|
3419046 | May 1984 | DEX |
Number | Name | Date | Kind |
---|---|---|---|
2831476 | Wilson | Apr 1958 | |
3239914 | Shirakura | Mar 1966 | |
4105012 | Hini | Aug 1978 | |
4646710 | Schmid et al. | Mar 1987 |
Entry |
---|
Journal of Physics E (Great Britain), Jan. 1971, vol. 4, pp. 54-56, C. S. Dickinson. |