| Number | Name | Date | Kind |
|---|---|---|---|
| 1388505 | Bamforth | Aug 1921 | |
| 3460834 | Nickel | Aug 1969 | |
| 3768811 | Goldfarb et al. | Oct 1973 | |
| 3863926 | White et al. | Feb 1975 | |
| 4277066 | Hough | Jul 1981 |
| Number | Date | Country |
|---|---|---|
| 715927 | Aug 1965 | CAX |
| 758568 | Oct 1956 | GBX |
| 1321071 | Jun 1973 | GBX |
| Entry |
|---|
| "Box Clever", Games and Puzzles, 1977, p. 20. |