00473nam a2200169 a 450000500170000008200210001710000180003824500270005626000360008330000230011969000270014270000160016996400250018599700120021099900150022295200660023720251203090445.0  a515.64,bDD, Gel  aGelfand, I.M.  aCalculus of variations  aNew JerseybPrentice-Hallc1963  avii, 232p., 22 cm.  aCalculus of variations  aFomin, S.V.  bEngc100de010fg_  a19548 W  c8252d8252  02104070aPUbPUd1998-04-08l0o515.64, DD, Gelp19548yBK