| Number | Name | Date | Kind |
|---|---|---|---|
| 3464701 | Mahoney | Sep 1969 | |
| 3884474 | Harper | May 1975 | |
| 4184685 | Wilson | Jan 1980 | |
| 4204685 | Jones | May 1980 | |
| 4883278 | Scott | Nov 1989 | |
| 5085440 | Van Daur | Feb 1992 |
| Number | Date | Country |
|---|---|---|
| 2550336 | May 1977 | DEX |
| 1283840 | Aug 1972 | GBX |
| Entry |
|---|
| The Way to Play by the Diagram Group, Paddington Press Ltd. pp. 28-29, 1975. |
| Spencer Gifts Catalog "Now! Play Chess In 3-D", Sep. 9, 1970. |