1. Analytic properties of wave fields;Apel’tsin,1990
2. The singularities of the continuation of wave fields;Kyurkchan;Phys Usp,1996
3. On the method of auxiliary currents and sources in problems of wave diffraction;Kyurkchan;Radio Eng Electron Phys,1984
4. About approximate solution of mathematical physics problems;Kupradze;Usp Math Nauk,1967
5. Fundamental functions in approximate solutions of the boundary problems;Aleksidze,1991