| Number | Date | Country | Kind |
|---|---|---|---|
| 87 06722 | May 1987 | FRX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2859659 | Fenske et al. | Nov 1958 | |
| 3364606 | Wengryn | Jan 1968 | |
| 4026644 | Tsuchida et al. | May 1977 | |
| 4254552 | Samis | Mar 1981 | |
| 4609268 | Crawford | Sep 1986 |
| Number | Date | Country |
|---|---|---|
| 0007125 | Jan 1980 | EPX |
| 0253081 | Jan 1988 | EPX |
| 1503720 | Dec 1967 | FRX |
| 2346736 | Oct 1977 | FRX |
| 344182 | Mar 1931 | GBX |
| Entry |
|---|
| "New PNC Programming Aid" Newing Hall Ltd.-Metalworking Production, vol. 129, No. 2, Feb. 1985-p. 67. |