@article{DAN_1963_151_1_a9,
     author = {A. S. Pekelis and L. E. Sadovskii},
     title = {Projectives of a torsion-free metabelian group},
     journal = {Doklady Akademii Nauk},
     pages = {42--44},
     publisher = {mathdoc},
     volume = {151},
     number = {1},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1963_151_1_a9/}
}