Authors
Sebastian Saniuk
University of Zielona Gora Faculty of Economics and Management ul. Podgórna 50,, Zielona Góra, Poland
Anna Saniuk
University of Zielona Gora Faculty of Mechanical Engineering ul. Prof. Z. Szafrana 4,, Zielona Góra, Poland
© 2018 Sebastian Saniuk, Anna Saniuk, published by STE Group sp. z.o.o.
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.