1. BUCHAU, J., ‘Instantaneous versus averaged ionosphere’, Air Force Surveys in Geophysics No. 241 (Air Force Systems Command, United States Air Force), 1 (1972)
2. ‘F-layer ionisation troughs deduced from Alouette data’;MULDREW;J. Geophys. Res.,1965
3. ionospheric Radio Propagation;DAVIES,1965
4. Sun, Earth and Radio—an Introduction to the Ionosphere and Magnetosphere;RATCLIFFE,1970
5. Introduction to Ionospheric Physics;RISHBETH,1969