@article{1178240691,
author = {Ii, Kiyotaka},
title = {On the isometric structure of Riemannian manifolds of non-negative Ricci curvature containing a compact hypersurface without focal point},
journal = {Tohoku Math. J. (2)},
volume = {29},
number = {4},
year = {1977},
pages = { 1-8},
language = {en},
url = {http://dml.mathdoc.fr/item/1178240691}
}
Ii, Kiyotaka. On the isometric structure of Riemannian manifolds of non-negative Ricci curvature containing a compact hypersurface without focal point. Tohoku Math. J. (2), Tome 29 (1977) no. 4, pp. 1-8. http://gdmltest.u-ga.fr/item/1178240691/