%0 Journal Article
%A I. K. Babenko
%T Periodic trajectories in three-dimensional Birkhoffs billiards
%J Sbornik. Mathematics
%D 1992
%P 1-13
%V 71
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/SM_1992_71_1_a0/
%G en
%F SM_1992_71_1_a0