@article{AL_1990_29_3_a5,
     author = {D. G. Khramtsov},
     title = {On the fundamental group of a 3-manifold},
     journal = {Algebra i logika},
     pages = {345--349},
     year = {1990},
     volume = {29},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1990_29_3_a5/}
}