@article{ZNSL_1999_261_a12,
     author = {N. D. Lebedeva},
     title = {On isometric immersion of closed manifolds of nonnegative curvature},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {187--193},
     year = {1999},
     volume = {261},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1999_261_a12/}
}