%0 Journal Article
%A M. M. Lavrent'ev
%T The maximum principle in the solutions of strongly elliptical second order systems
%J Doklady Akademii Nauk
%D 1957
%P 175-176
%V 116
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1957_116_2_a2/
%G ru
%F DAN_1957_116_2_a2