| Number | Date | Country | Kind |
|---|---|---|---|
| 20087 A/87 | Apr 1987 | ITX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3201246 | Allen et al. | Aug 1965 | |
| 3994730 | Frank et al. | Nov 1976 | |
| 4172728 | Sincius et al. | Oct 1979 | |
| 4264716 | Vincent et al. | Apr 1981 | |
| 4482626 | Twist et al. | Nov 1984 | |
| 4588677 | Ishikawa et al. | May 1986 | |
| 4596764 | Ishimaru | Jun 1986 | |
| 4693956 | Marchesano | Sep 1987 |
| Number | Date | Country |
|---|---|---|
| 0136582 | Sep 1983 | EPX |
| Entry |
|---|
| Research Disclosure 18837, published Dec. 1979. |