2x2x6A highly customized 4x4x4 cube.
2x3x4 (bandaged 4x4x4)A bandaged 4x4x4 variation that functions exactly like the Wall Cube, but is solved in a slightly different configuration.
2x4x4 (bandaged 4x4x4)A bandaged 4x4x4 variation that tries to simulate a 2x4x4, but turns out to be a much more complex puzzle.
Adventures in Group TheoryThis book is a must have for true theorists. This is one of the few books which do not give solutions to specific puzzles. This books goes really deep into the mathematical basis under Rubiks Cube and its relatives.

