Institute for Nuclear Research and Nuclear Energy;
Bulgarian Academy of Sciences;
Sofia;
Bulgaria;
University “Sts. Cyril and Methodius”;
Seismological Observatory;
Skopje;
Macedonia;
Ilya State University;
Tbilisi;
Georgia;
National Institute for Geophysics;
Geography and Geodesy;
Bulgarian Academy of Sciences;
Sofia;
Bulgaria;
Space Research and Technology Institute;
Bulgarian Academy of Sciences;
Sofia;
Bulgaria;
Earthquakes; Geomagnetism; Earth; Sun-Moon; Tide; Regional; Seismic; Activity; Forecasting;