@article{SM_1991_68_1_a0,
     author = {A. A. Fomin},
     title = {Torsion-free {Abelian} groups of rank~3},
     journal = {Sbornik. Mathematics},
     pages = {1--17},
     year = {1991},
     volume = {68},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1991_68_1_a0/}
}