1. Department of Economics, Koszalin University of Technology, Faculty of Economic Sciences, Koszalin, Poland; Department of Business Administration, Western Norway University of Applied Sciences, Sogndal, Norway
2. Department of Finance, Koszalin University of Technology, Faculty of Economic Sciences, Koszalin, Poland
3. Department of Economics, Koszalin University of Technology, Faculty of Economic Sciences, Koszalin, Poland