 Co-author of "The Rubik's Cube Compendium" (written by David Singmaster, Ernő Rubik, Gerzson Kéri, György Marx, Tamás Varga and Tamás Vekerdy), Oxford University Press, 1987.He attended the 2007 World Championship in Budapest.He also gave a lecture and autograph session at the "Bridges-Pecs" conference ("Bridges between Mathematics and the Arts") in July 2010.