Severina Djorova, Maria Nikolova. DETERMINATION OF DEPTH PARAMETERS OF SUBSURFACE VOIDS USING GRAVIMETRIC AND GLOBAL NAVIGATION SATELITTE SYSTEMS MEASUREMENTS. 24th International Multidisciplinary Scientific GeoConference Proceedings SGEM 2024, Science and Technologies in Geology, Exploration And Mining, Vol 24, Issue 1.1, 2024, pp. 475-482. https://doi.org/10.5593/sgem2024/1.1/s05.60