1. Nonlinear Analysis Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam;
2. Faculty of Mathematics and Statistics, Ton Duc Thang University, Ho Chi Minh City, Vietnam;
3. Department of Mathematics, Payame Noor University, Tehran, Islamic Republic of Iran;
4. Faculty of Electrical Engineering, University of Banja Luka, Patre 5, Banja Luka, Bosnia and Herzegovina;
5. Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marie 16, Beograd, Serbia