1. Department of Mathematical Sciences, Sharif University of Technology, Tehran, Iran
2. Department of Mathematics, Faculty of Science, Shahid Rajaee Teacher Training University, Tehran, Iran
3. Faculty of Engineering Modern Technology, Amol University of Special Modern Technologies, Amol, Iran
4. Krasovskii Institute of Mathematics and Mechanics, Yekaterinburg, Russia
5. Sobolev Institute of Mathematics, Novosibirsk, Russia
6. Novosibirsk State University, Novosibirsk, Russia
7. Chelyabinsk State University, Chelyabinsk, Russia