Authors
Renata Walczak
Warsaw University of Technology, College of Economics and Social Sciences,, Warsaw, Poland
Anikó Kálmán
Budapest University of Technology and Economics,, Budapest, Hungary
© 2018 Renata Walczak, Anikó Kálmán, published by Warsaw University of Technology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.