00370nam a2200109Ia 4500008004100000082002000041100001700061245008700078260003600165300002100201490003800222260423b        |||||||| |||| 00| 0 eng d  a515.35bL763.PS  aLions, J. L.  aPerturbations singulieres dans les problemes aux limites et en controle optimalb/  aBerlin:bSpringer-Verlag,c1973  axii, 645p. Bibl.  aLecture notes in Mathematicsv323