Number | Date | Country | Kind |
---|---|---|---|
3-39728 | Dec 1991 | JPX |
Number | Name | Date | Kind |
---|---|---|---|
3261091 | Van Den Driest | Jul 1966 | |
3264733 | Tiemes et al. | Aug 1966 | |
3919770 | Sakai et al. | Nov 1975 | |
4192065 | Tietjens | Mar 1980 | |
4630370 | Hamada | Dec 1986 | |
4635360 | Tanahashi | Jan 1987 |