1. University of Debrecen, Department of Inorganic and Analytical Chemistry, 4010 Debrecen, Hungary, Fax: (internat.) +36‐52/489‐667
2. ICN Hungary LTD, 4440 Tiszavasvári, Hungary
3. University of Pécs, Institute of Organic and Medicinal Chemistry, 7643 Pécs, Hungary