00878nam0-22002891i-450-990002549040403321000254904FED01000254904(Aleph)000254904FED0100025490420000920d1955----km-y0itay50------baENGPlane waves and Spherical MeansApplied to Partial Differential EquationsFritz John.New YorkInterscience1955.172 p.24 cmEquazioni differenziali alle derivate parziali, Equazioni differenziali ed integrali519John,Fritz331219ITUNINARICAUNIMARCBK990002549040403321MX-B-73034297MASMX-B-74010830MASMASPlane waves and spherical means108203UNINAING01