| Date | Subject |
|---|---|
| January 22, 1981 | Correction to "Symmetry and Local Maxima" |
| February 1, 1981 | Algorithm for finding cube group orders |
| February 1, 1981 | Algorithm for computing cube group orders |
| June 15, 1982 | Patterns for Rubik's Revenge |
| January 28, 1983 | The shortest sequence of moves. |