Nikolay Dimitrov, Ivan Georgiev, Petar Danchev. "VELOCITY FIELD IN SOUTHWEST BULGARIA OBTAINED FROM GNSS DATA." SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 21st SGEM International Multidisciplinary Scientific GeoConference Proceedings 2021, Informatics, Geoinformatics and Remote Sensing (2021): 229-236. https://doi.org/10.5593/sgem2021/2.1/s09.57