| Marco van Eekelen one of the Rubik's cube pioneers in the Netherlands in
1981, also held a presentation, about his famous moments in 1981, like the Dutch
Rubik's Cube contensts he won. He also wrote a scription during his study on
solving the Halpern-Pyramid, he was very supprised
to see this puzzle I build in my collection. He and a friend solved the
puzzle on paper he did not know it was actually build. |