1. Faculty of Science, Department of Inorganic Chemistry, P. J. Šafárik University, Košice, Slovak Republic
2. Faculty of Science, Department of Inorganic Chemistry, Charles University, Praha, Czech Republik
3. Faculty of Education, Department of Chemistry, J. Selye University, Komárno, Slovak Republic
4. NMR Laboratory, Faculty of Science, Department of Organic Chemistry, P.J.Šafárik University, Košice, Slovak Republic
5. Faculty of Science, Department of Organic Chemistry, P.J. Šafárik University, Košice, Slovak Republic