Authors
Marian Oliński
University of Warmia and Mazury, Olsztyn, Poland
Piotr Szamrowski
University of Warmia and Mazury, Olsztyn, Poland
© 2019 Marian Oliński, Piotr Szamrowski, published by Faculty of Economic Sciences, University of Warsaw
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.