@article{DAN_1989_305_6_a5,
     author = {V. B. Marenich},
     title = {The structure of open manifolds of nonnegative curvature},
     journal = {Doklady Akademii Nauk},
     pages = {1311--1314},
     year = {1989},
     volume = {305},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_305_6_a5/}
}