00305cam a2200169   450000500170000024500420001702000050005910000220006404400050008625000050009104100080009630000050010450000050010983000050011426000090011908200070012820260711133824.0  aEcuaciones diferenciales ordinariasb  a  aPontriaguin, L.S.  a  a  aspa  a  a  v  abc  ab