Kirilova, K. 2023. OPTIMAL GEOPOTENTIAL MODELS OF THE EARTH’S GRAVITATIONAL FIELD FOR THE TERRITORY OF SOUTHWESTERN BULGARIA - RILA MOUNTAIN: OPTIMAL GEOPOTENTIAL MODELS OF THE EARTH’S GRAVITATIONAL FIELD FOR THE TERRITORY OF SOUTHWESTERN BULGARIA - RILA MOUNTAIN. JOURNAL SCIENTIFIC AND APPLIED RESEARCH. 19, 1 (Mar. 2023), 67–71. DOI:https://doi.org/10.46687/jsar.v19i1.295.