@article{MZM_1981_29_2_a8,
     author = {S. V. Buyalo},
     title = {Manifolds of nonpositive curvature with small volume},
     journal = {Matemati\v{c}eskie zametki},
     pages = {243--252},
     publisher = {mathdoc},
     volume = {29},
     number = {2},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1981_29_2_a8/}
}