| Number | Name | Date | Kind |
|---|---|---|---|
| 3964195 | Jordan | Jun 1976 | |
| 4148273 | Hollingsworth et al. | Apr 1979 | |
| 4614360 | Sheehan et al. | Sep 1986 | |
| 4815767 | Lambert | Mar 1989 | |
| 5031937 | Nellhaus | Jul 1991 | |
| 5102169 | Mayfield | Apr 1992 | |
| 5176522 | Robertson, Jr. | Jan 1993 | |
| 5207580 | Strecher | May 1993 | |
| 5261702 | Mayfield | Nov 1993 |
| Number | Date | Country |
|---|---|---|
| 3540736 | May 1987 | DEX |
| 1450281 | Sep 1976 | GBX |
| Entry |
|---|
| Miller's Office Products Catalogue, 1989, pp. 284, 301, 302, 304, & 305, 288, 289. |