Theory Division, CERN, 1211 Geneva 23, Switzerland
Mark D. Goodsell
Sorbonne Universités, UPMC Univ. Paris 06, UMR 7589, LPTHE, 75005 Paris, France
Michal Malinský
Institute of Particle and Nuclear Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 180 00 Praha 8, Czech Republic