1. Department of Management, Faculty of Organization and Management, Silesian University of Technology, 26–28 Roosevelt Street, 41-800 Zabrze, Poland
2. Department of Management, Faculty of Applied Sciences, WSB University, 41-300 Dabrowa Gornicza, Poland
3. The London Academy of Science and Business, 120 Baker St., London W1U 6TU, UK
4. Department of Marketing, Sumy State University, 2, Rymskogo-Korsakova St., 40007 Sumy, Ukraine