1. Department of Mechanics, State University of Novi Pazar, Vuka Karadzica bb, Novi Pazar, Serbia
2. Faculty of Technical Sciences, University of Kosovska Mitrovica, Kneza Milosa 7, Kosovska Mitrovica, 38220, Serbia
3. Department of Mathematics and Informatics, Faculty of Natural Sciences and Mathematics, University of Novi Sad, Trg Dositeja Obradovica 4, Novi Sad, 21000, Serbia