1. D. Bilitza, “International Reference Ionosphere 2000,” Radio Sci. 36(2), 261–275 (2001).
2. G. G. Bowman, “A Review of Some Recent Works on Midlatitude Spread-F Occurrence as Detected by Ionosondes,” J. Geomagn. Geoelectr. 42(2), 109–138 (1990).
3. G. G. Bowman, “Upper Atmosphere Neutral-Particle Density Variations Compared with Spread-F Occurrence Rates at Locations around the World,” Ann. Geophys. 10(9), 676–682 (1992).
4. B. E. Bryunelli and A. A. Namgaladze, Physics of the Ionosphere (Nauka, Moscow, 1988) [in Russian].
5. M. G. Deminov and E. V. Nepomnyashchaya, “Dependence of the Midlatitude Spread-F Probability on Solar and Geomagnetic Activity,” Geomagn. Aeron. 43(6), 763–769 (2003) [Geomagn. Aeron. 43, 711–717 (2003)].