1. Catalog of the electron concentration profiles in the D region of the midlatitude ionosphere;Belikovich,1983
2. Spatial-time variations in the radio wave absorption in the ionosphere;Belkina;Geomagn. Aeron.,1968
3. Electron density in the D region as given by the International Reference Ionosphere;Bilitza,1981
4. Diurnal, seasonal and solar-cycle variations of electron densities in the ionospheric D and E regions;Bremer;J. Atmos. Terr. Phys.,1977