Wilfried Imrich
Emer. O. Univ. Prof. Dr. phil.
Chair of Applied Mathematics
Department Mathematics and Information Technology
Montanuniversität Leoben
Franz Josef-Straße 18
8700 Leoben, Austria
Tel +43 3842 402 1717, Fax -1702
e-mail: imrich(at)unileoben.ac.at