Kriegsmann, Gregory A.; Morawetz, Cathleen S. Solving the Helmholtz equation for exterior problems with variable index of refraction. I. (English) Zbl 0469.65084 SIAM J. Sci. Stat. Comput. 1, 371-385 (1980). MSC: 65Z05 65N22 65N06 35J05 78A45 PDFBibTeX XMLCite \textit{G. A. Kriegsmann} and \textit{C. S. Morawetz}, SIAM J. Sci. Stat. Comput. 1, 371--385 (1980; Zbl 0469.65084) Full Text: DOI Link
Kriegsmann, Gregory A.; Morawetz, Cathleen Synge Numerical methods for solving the wave equation with variable index of refraction. (English) Zbl 0448.65065 Boundary and interior layers - computational and asymptotic methods, Proc. Conf., Dublin 1980, 118-123 (1980). MSC: 65N22 35J05 65F10 78A45 78A05 PDFBibTeX XML
Kriegsmann, Gregory; Morawetz, Cathleen S. Numerical solutions of exterior problems with the reduced wave equation. (English) Zbl 0393.65042 J. Comput. Phys. 28, 181-197 (1978). MSC: 65N22 35J05 65N06 PDFBibTeX XMLCite \textit{G. Kriegsmann} and \textit{C. S. Morawetz}, J. Comput. Phys. 28, 181--197 (1978; Zbl 0393.65042) Full Text: DOI