00876nam0-22002891i-450-99000001325040332120041001085459.0000001325FED01000001325(Aleph)000001325FED0100000132520020821d1955----km-y0itay50------baitaa---a---001yyPlane waves and spherical meansapplied to partial differential equationsFritz John.New YorkInterscience publishers1955VIII, 172 p.ill.23 cmInterscience tracts in pure and applied mathematics2515John,Fritz331219ITUNINARICAUNIMARCBK99000001325040332113 K 13 3023508FINBCFINBCPlane waves and spherical means108203UNINA