@article{10_4153_CMB_1974_134_4,
     author = {Charnow, A.},
     title = {A {Note} on {Torsion} {Free} {Groups} {Generated} by {Pairs} of {Matrices}},
     journal = {Canadian mathematical bulletin},
     pages = {747--748},
     year = {1975},
     volume = {17},
     number = {5},
     doi = {10.4153/CMB-1974-134-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1974-134-4/}
}