Manukyan, Y. 2018. AT THE FACULTY OF GEOLOGY AND GEOGRAPHY OF THE INTERNATIONAL CONFERENCE DEDICATED TO THE 100th ANNIVERSARY OF YSU. Proceedings of the YSU C: Geological and Geographical Sciences. 52, 3 (247) (Dec. 2018), 215–217. DOI:https://doi.org/10.46991/PYSU:C/2018.52.3.215.