@article{MM2_1988__61_4_155318,
     author = {Martin Strake},
     title = {A splitting theorem for open nonnegatively curved manifolds.},
     journal = {Manuscripta mathematica},
     pages = {315--326},
     publisher = {mathdoc},
     volume = {61},
     number = {4},
     year = {1988},
     zbl = {0653.53023},
     url = {http://geodesic.mathdoc.fr/item/MM2_1988__61_4_155318/}
}