1. Asymptotic Methods of Short Wave Diffraction;Babich,1972
2. Ray Optical Calculation of Modes Excited by Sources and Scatterers in Weakly Inhomogeneous Ducts;Batorsky;Radio Sci.,1971
3. The Singularity Expansion Method;Baum,1976
4. Local Properties of Radiation in Lossy Media;Bertoni;IEEE Trans. Antennas Propagat,1971
5. Radio Ray Tracing in Complex Space;Budden;Proc. R. Soc.,1971