Pg. Mezey et N. Trinajstic, TOPOLOGICAL CHEMISTRY - PROCEEDINGS OF THE INTERNATIONAL-CONFERENCE ON TOPOLOGICAL CHEMISTRY - ZENTRUM-FUR-INTERDISZIPLINARE-FORSCHUNG-(ZIF) - UNIVERSITAT-BIELEFELD - BIELEFELD, GERMANY - 28 OCTOBER 1 NOVEMBER1991, Journal of mathematical chemistry, 13(1), 1993, pp. 210000001-210000001