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@article{AA_1999_11_2_a2, author = {S. V. Buyalo and V. L. Kobel'skii}, title = {Generalized graph-manifolds of nonpositive curvature}, journal = {Algebra i analiz}, pages = {64--87}, publisher = {mathdoc}, volume = {11}, number = {2}, year = {1999}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/AA_1999_11_2_a2/} }
S. V. Buyalo; V. L. Kobel'skii. Generalized graph-manifolds of nonpositive curvature. Algebra i analiz, Tome 11 (1999) no. 2, pp. 64-87. http://geodesic.mathdoc.fr/item/AA_1999_11_2_a2/