| Number | Date | Country | Kind |
|---|---|---|---|
| 9217440.8 | Aug 1992 | GBX | |
| 9217559.5 | Aug 1992 | GBX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4522401 | Gustafson | Jun 1985 | |
| 4553754 | Wiggs et al. | Nov 1985 | |
| 4557484 | Sherman, Jr. et al. | Dec 1985 | |
| 4558866 | Alford | Dec 1985 | |
| 5199711 | Pataki et al. | Apr 1993 |
| Number | Date | Country |
|---|---|---|
| 1188342 | Jun 1985 | CAX |
| 0042695 | Dec 1981 | EPX |
| 3116973 | Nov 1982 | DEX |
| 170062 | Dec 1977 | HUX |
| 205017B | Mar 1992 | HUX |
| WO8301008 | Mar 1983 | WOX |
| 1391073 | Apr 1988 | SUX |
| 8301203 | Apr 1983 | WOX |
| 8703212 | Jun 1987 | WOX |
| Entry |
|---|
| "Puzzles" by Slorum & Botermans, 1986, Plenary Publications, International, pp. 138-139. |