http://www.xs4all.nl/~gp/PolyominoSolver/Polyomino.html http://reglos.de/pentominos/ http://kevingong.com/Polyominoes/index.html http://lonestar.texas.net/~jenicek/pentomin/pentomin.html http://members.cts.com/crash/h/hindskw/pentomno.html http://www.xs4all.nl/~gp/pentomino.html Jürgen Köller