Authors
grzegorz.maciejewski@ue.katowice.pl
University of Economics, Faculty of Economics, Department of Market and Consumption, Katowice, Poland
grzegorz.maciejewski@ue.katowice.pl
© 2020 Grzegorz Maciejewski, published by ŁUKASIEWICZ RESEARCH NETWORK – INSTITUTE OF AVIATION
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.