00813nam0-22002531i-450-99000113252040332120071108140521.0000113252FED01000113252(Aleph)000113252FED0100011325220001205d1964----km-y0itay50------baengPertubation Techniques in Mathematics, Physics, and EngineeringR. BellmanNew YorkHolt Rinehart and Winston1964Athena seriesSelected topics in mathematicsBellman,Richard Ernest<1920-1984>121312ITUNINARICAUNIMARCBK99000113252040332121-I-55697MA1MA1Pertubation Techniques in Mathematics, Physics, and Engineering345348UNINA