Belkhelfa, M. and Mahi, F. (2019) “Second order parallel tensors on $S$ -manifolds and semi-parallel hypersurfaces of $S$ -space forms”, Ukrains’kyi Matematychnyi Zhurnal, 71(10), pp. 1422-1429. Available at: http://umj.imath.kiev.ua/index.php/umj/article/view/1524 (Accessed: 2October2022).