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Iwona Bąk
West Pomeranian University of Technology, Szczecin, Faculty of Economics, Department of Mathematical Applications in Economics, Janickiego 31, 71-101 Szczecin, Poland
Beata Szczecińska
West Pomeranian University of Technology, Szczecin, Faculty of Economics, Department of Systems Analysis and Finance, Janickiego 31, 71-101 Szczecin, Poland