Manukyan, S.S. “GEOPHYSICAL METHODS APPLICATION AT THE INVESTIGATION OF HYDROTECHNICAL TUNNELS TRACES IN MOUNTAIN-FOLDED AREAS”. Proceedings of the YSU C: Geological and Geographical Sciences, vol. 51, no. 2 (243), Aug. 2017, pp. 81-87, doi:10.46991/PYSU:C/2017.51.2.081.