Rubik's Revenge: The Group Theoretical Solution
Mogens Esrom Larsen · American Mathematical Monthly · 1985
Introduction. Recently Rubik and Ideal Toy have supplied us with an analog to Rubik's Cube with four slices instead of three. It is sold under the name of Rubik's Revenge; see Fig. 1. The advantage is that no solution is offered besides the toy. This is however a disadvantage too, because the Revenge is even more difficult to solve without mathematics than the Cube and might hence disappoint a few puzzlers. I shall return to these difficulties at the end. A general mathematician might think that this is just some more of the same. But such an