@article{1077465589,
author = {Gerstenhaber, Murray},
title = {A characterization of the modular group and certain similar
groups},
journal = {Duke Math. J.},
volume = {21},
number = {1},
year = {1954},
pages = { 113-121},
language = {en},
url = {http://dml.mathdoc.fr/item/1077465589}
}
Gerstenhaber, Murray. A characterization of the modular group and certain similar
groups. Duke Math. J., Tome 21 (1954) no. 1, pp. 113-121. http://gdmltest.u-ga.fr/item/1077465589/