1. Blagoveshchenskii, D.V., Short Waves in Anomaly Radio Channels, Saarbrücken, Germany: Lambert Academic, 2011.
2. Carson, J.R., Reciprocal theorems in radio communications, Proc. IRE, 1929, vol. 19, pp. 952–961.
3. Davies, K., Ionospheric Radio Waves, Waltham, MA: Blaisdell, 1969.
4. Feinberg, E.L., Rasprostranenie radiovoln vdol' zemnoi poverkhnosti (Radio Wave Propagation Along the Earth’s Surface), Moscow: Nauka. Fizmatlit, 1999.
5. Kerblai, T.S. and Kovalevskaya, E.M., Calculation of maximum usable frequency under horizontal inhomogeneity of the ionosphere, Geomagn. Aeron., 1967, vol. 7, no. 1, pp. 123–127.