1. Abramowitz , M. J. A. Stegun Handbook of Mathematical FunctionsNBS Applied Math. Ser. 55 1964
2. Bean , B. R. E. J. Dutton Radio MeteorologyNBS Monogr. 92 1966
3. Bean , B. R. G. D. Thayer CRPL Exponential Reference AtmosphereNBS Monog. 4 1959
4. Range error compensation for a troposphere with exponentially varying refractivity;Freeman;J. Res. NBS, Radio Propagat.,1962
5. A formula for radio ray refraction in an exponential atmosphere;Thayer;J. Res. NBS, Radio Propagat.,1961