00691nam0-22002531i-450-990001229610403321000122961FED01000122961(Aleph)000122961FED0100012296120000920d1963----km-y0itay50------baengVariational Methodsde LAVRENT'EV M.A.GroningenRADOK NOORDHOFF Ltd.1963.Lavrentiev,Mikhail Aleksevitch<1900-1980>344599ITUNINARICAUNIMARCBK9900012296104033214-F-146632MA1MA135J20Variational Methods382057UNINAING01