@article{IVM_1994_10_a4,
     author = {P. A. Krylov},
     title = {When is the extension group $Ext(A,B)$ torsion-free?},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {33--41},
     publisher = {mathdoc},
     number = {10},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1994_10_a4/}
}