%0 Journal Article
%A P. I. Lizorkin
%T The Dirichlet principle for the Beltrami equation in a semi-space
%J Doklady Akademii Nauk
%D 1960
%P 761-764
%V 134
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1960_134_4_a4/
%G ru
%F DAN_1960_134_4_a4