%0 Journal Article
%A Konopka 

 Czesław,
%T On extrinsic spheres in 

 a locally product riemannian manifold
%J Novi Sad Journal of Mathematics
%D 1992
%P 141-148
%V 22
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/NSJOM_1992_22_1a_13/
%F NSJOM_1992_22_1a_13