Kovalchuk A, Shkut O. COMPARATIVE ANALYSIS OF THE 1977 BALTIC SEA LEVEL SYSTEM AND THE EUROPEAN VERTICAL REFERENCE SYSTEM WITHIN THE FRAMEWORK OF TRANSITION TO A UNIFIED EUROPEAN SPATIAL DATA INFRASTRUCTURE. Вісник (військові). 2025;(3(63):93-98. doi:10.17721/1728-2217.2025.63.93-98