TY  - CPAPER
AU  - Rumiana Bojilova
AU  - Plamen Mukhtarov
TI  - AN EMPIRICAL MODEL FOR FORECASTING THE CRITICAL FREQUENCY OF THE IONOSPHERIC E-REGION OVER BULGARIA
T2  - SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 21st SGEM International Multidisciplinary Scientific GeoConference Proceedings 2021, Science and Technologies in Geology, Exploration And Mining
PY  - 2021
SP  - 403
EP  - 410
DO  - 10.5593/sgem2021/1.1/s05.075
PB  - STEF92 Technology
ER  -