%0 Journal Article
%A M. M. Popov
%T On the Morse index calculation and the prolongation of the ray formulae beyond caustics
%J Zapiski Nauchnykh Seminarov POMI
%D 2015
%P 225-235
%V 438
%I mathdoc
%U http://geodesic.mathdoc.fr/item/ZNSL_2015_438_a13/
%G ru
%F ZNSL_2015_438_a13