@article{JMAG_1996_3_a14,
     author = {A. L. Yampol'skii},
     title = {On the vertical strong sphericity of {Sasaki} metric of tangent sphere bundles},
     journal = {\v{Z}urnal matemati\v{c}eskoj fiziki, analiza, geometrii},
     pages = {446--455},
     publisher = {mathdoc},
     volume = {3},
     year = {1996},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/JMAG_1996_3_a14/}
}