Published Online: Dec 22, 2018
Page range: 103 - 108
DOI: https://doi.org/10.2478/mgrsd-1994-060115
© 2018 Urszula Kossowska-Cezak, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.
Urszula Kossowska-Cezak