00680nam0-22002531i-450-990001186840403321000118684FED01000118684(Aleph)000118684FED0100011868420000920d1973----km-y0itay50------baengPertubation Methodsby NAYFEH A.H.New York [etc.]John Wiley1973Pure and applied mathematicsNayfeh,Ali Hassan346872ITUNINARICAUNIMARCBK99000118684040332114-H-213402MA1MA1Pertubation Methods342505UNINAING01