%0 Journal Article
%A Barrett, John H.
%T Matrix systems of second order differential equations
%J Portugaliae mathematica
%D 1955
%P 79-89
%V 14
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/PORMA_1955__14_3_114755/
%G en
%F PORMA_1955__14_3_114755