%0 Journal Article
%T Joint sessions of the Petrovskii Seminar on Differential Equations and Mathematical Problems of Physics and of the Moscow Mathematical Society (sixteenth session,  18--21~January~1994)
%J Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1994
%P 79-143
%V 49
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RM_1994_49_4_a3/
%G en
%F RM_1994_49_4_a3