Georgi Zhelezov, Velimira Stoyanova. DETERMINATION OF THE COASTAL ZONE OF DANUBE RIVER IN BULGARIA. SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 21st SGEM International Multidisciplinary Scientific GeoConference Proceedings 2021, Ecology, Economics, Education and Legislation, 2021, pp. 51-58. https://doi.org/10.5593/sgem2021/5.1/s20.014