“…The Green's function formulation has been favoured by many authors, including Baldwin and Heins (1954), Twersky (1956), Verbitskii (1974, Kalhor (1980) and Kalhor and I1yas (1982). The point-(a) (b) matching method was used by Neureuther and Zaki (1968), Ikuno and Yasuura (1973), Mayhan and Tsai (1976) and Kalhor (1980). The method of plane-wave expansion has been extensively employed; Richmond (1980) andHugonin et al (1981), among others.…”