Sardaryan, A.S., et al. “FEATURES RADIATION FIELD IN NATURAL AND ARTIFICIAL UNDERGROUND CAVITIES: (according to Observations in Мozrov and Аrji Caves)”. Proceedings of the YSU C: Geological and Geographical Sciences, vol. 53, no. 3 (250), Dec. 2019, pp. 161-5, doi:10.46991/PYSU:C/2019.53.3.161.