1. Faculty of Electrical Engineering, University of Banja Luka, Patre 5, 78000 Banja Luka, Bosnia and Herzegovina
2. Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11000 Beograd, Serbia
3. Faculty of Transport and Traffic Engineering, University of East Sarajevo, Vojvode Mišića 52, 53000 Doboj, Bosnia and Herzegovina
4. Department of Mathematics, Buein Zahra Technical University, Buein Zahra, Qazvin, Iran
5. Department of Mathematics, Gilan-E-Gharb Branch, Islamic Azad University, Gilan-E-Gharb, Iran