About this article
Published Online: Jun 30, 2018
Page range: 20 - 35
Received: Jan 11, 2018
Accepted: Mar 15, 2018
DOI: https://doi.org/10.2478/cait-2018-0025
Keywords
© 2018 Penka V. Georgieva, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
Georgieva, Penka V.
Burgas Free UniversityBurgas, Bulgaria