Dear friends! We are glad to announce 5 years Anniversary of our project. We celebrate it with the 21^st issue of the journal and with a new format from the archive of the journal where you can observe all covers of the magazine in a row. It is the second time when our issue is decorated with the work by a photographer Alexander Yermolitskyi. We continue our collaboration with the constant authors and we are glad to introduce with the new authors (there are famous scholars among them which works appeared in the issue the first time). Six more names were added to the present circle of the authors in the issue. Later, PDF-version will be published on our web-page, and the materials will also be uploaded to the database of the Russian Science Citation Index (RSCI). We hope that the present issue will be useful in your work, will be interesting for reading and will help the beginners in science. We welcome the papers for the next issue.