Editor General: Aleksander Posern-Zieliński
The issue is currently unavailable online, as availability of the issue is limited. The editorial council is currently trying to provide the online access to the articles and other contents.
Copyright by PTSL © 2021. With all rights reserved unless otherwise noted. The Journal supports Open Access principles and practices in which research outputs are distributed online, free of cost or other access barriers. Creative Commons open access licenses are applied wherever possible. Creative Commons licensing is mandatory for future submissions.
This work was supported by the Ministry of Science and Higher Education (Project ID 191/WCN/2019/1)