1. Raluca Ripan Institute of Research in Chemistry, Babes Bolyai University, 30 Fantanele Street, 400294 Cluj Napoca, Romania
2. Faculty of Economic Sciences, 1 Decembrie 1918 University of Alba Iulia, 15–17 Unirii Street, 510009 Alba Iulia, Romania
3. Faculty of Materials Engineering and Physics, Cracow University of Technology, 31-864 Cracow, Poland