Rumiana Bojilova, Plamen Mukhtarov. "LOCAL TIME DEPENDENCE OF THE IONOSPHERIC RESPONSE TO GEOMAGNETIC DISTURBANCES OVER BULGARIA." SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 20th International Multidisciplinary Scientific GeoConference Proceedings SGEM 2020, Science and Technologies in Geology, Exploration And Mining (2020): 615-622. https://doi.org/10.5593/sgem2020/1.2/s05.078