1. Faculty of Sciences and Mathematics, University of Niš, Niš, Serbia
2. Laboratory “Hybrid Methods of Modeling and Optimization in Complex Systems”, Siberian Federal University, Krasnoyarsk, Russia
3. Department of Economics, Division of Mathematics-Informatics and Statistics-Econometrics, National and Kapodistrian University of Athens, Athens, Greece
4. School of Business, Jiangnan University, Wuxi, China
5. Faculty of Information Technology, University of Oulu, Oulu, Finland