%0 Journal Article
%A Ferreira, José M.
%T Nonnegative point spectrum for differential equations with infinite delays
%J Portugaliae mathematica
%D 1981
%P 239-251
%V 40
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/PORMA_1981__40_2_115447/
%G en
%F PORMA_1981__40_2_115447