@article{CMH_1979__54_139774,
     author = {Ralph Strebel},
     title = {A note on groups with torsion-free abelianization and trivial multiplicator.},
     journal = {Commentarii mathematici Helvetici},
     pages = {147--158},
     publisher = {mathdoc},
     volume = {54},
     year = {1979},
     zbl = {0389.20028},
     url = {http://geodesic.mathdoc.fr/item/CMH_1979__54_139774/}
}