1. Urban mobile radio propagation at 900 MHz;Ibrahim;Electronics Letters,1982
2. Radio propagation above 40MC over irregular terrain;Egli,1957
3. Systematic ionospheric electron density tilts (SITs) at mid-latitudes and their associated HF bearing errors;Tedd;Journal of Atmospheric and Terrestrial Physics,1985
4. The influence of large scale TIDs on the bearings of geographically spaced HF transmissions;Tedd;Journal of Atmospheric and Terrestrial Physics,1984
5. See ‘http://www.bbc.co.uk/rd/pubs/latest/index.html’