1. The wave equation in exterior domains;Lax, Peter D.;Bull. Amer. Math. Soc.,1962
2. 2. P. D. Lax and R. S. Phillips, Spectral theory for the wave equation, (to appear).
3. The decay of solutions of the exterior initial-boundary value problem for the wave equation;Morawetz, Cathleen S.;Comm. Pure Appl. Math.,1961
4. The limiting amplitude principle;Morawetz, Cathleen S.;Comm. Pure Appl. Math.,1962
5. 5. C. Wilcox, The initial-boundary value problem for the wave equation in an exterior domain with spherical boundary, Abstract No. 564-20, Notices Amer. Math. Soc. 6, No. 7 (1959).