1. Radio Wave Propagation and the Ionosphere;Al'pert;USSR Academy of Sciences,1960
2. On the altitude-time distribution of the electron concentration of the outer ionosphere and its stratum-inhomogeneous disturbance. I;Al'pert;Space Research VI, Proc. 6th Internatl. Space Sci. Symp.,1965
3. The normal E region of the ionosphere;Appleton;Proc. IRE,1959
4. Study of the lower ionosphere using partial reflection;Belrose;J. Geophys. Res.,1964
5. Radio scattering in the lower ionosphere;Booker;J. Geophys. Res.,1959