@article{IVM_1997_9_a10,
     author = {E. I. Yakovlev},
     title = {Sectional curvatures of manifolds of the {Kaluza--Klein} type},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {75--82},
     publisher = {mathdoc},
     number = {9},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1997_9_a10/}
}