@article{IVM_2006_6_a7,
     author = {E. N. Sosov},
     title = {On the metric space of all $N$-nets in a space of nonpositive curvature in the sense of {Busemann}},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {74--77},
     publisher = {mathdoc},
     number = {6},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2006_6_a7/}
}