%0 Journal Article
%A V. M. Shashkov
%T An existence theorem for an extremal problem in a~Hilbert space
%J Izvestiâ vysših učebnyh zavedenij. Matematika
%D 1981
%P 52-54
%N 8
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IVM_1981_8_a9/
%G ru
%F IVM_1981_8_a9