@article{Belkhelfa_Mahi_2019, title={Second order parallel tensors on $S$ -manifolds and semi-parallel hypersurfaces of $S$ -space forms}, volume={71}, url={https://umj.imath.kiev.ua/index.php/umj/article/view/1524}, abstractNote={UDC 515.12 <br&gt; We study a second order parallel symmetric tensor in an $\mathcal{S}$-manifold and we deduce that there is no semi-parallel hypersurface in $\mathcal{S}$-space forms $\widetilde{M}^{2n+s}(c)$ with $c eq s.$}, number={10}, journal={Ukrains’kyi Matematychnyi Zhurnal}, author={Belkhelfa, M. and Mahi, F.}, year={2019}, month={Oct.}, pages={1422-1429} }