Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MS2_1962__10_165791, author = {Leon Greenberg}, title = {Discrete {Subgroups} of the {Lorentz} {Group.}}, journal = {Mathematica Scandinavica}, pages = {85--107}, publisher = {mathdoc}, volume = {10}, year = {1962}, zbl = {0118.03902}, url = {http://geodesic.mathdoc.fr/item/MS2_1962__10_165791/} }
Leon Greenberg. Discrete Subgroups of the Lorentz Group.. Mathematica Scandinavica, Tome 10 (1962), pp. 85-107. http://geodesic.mathdoc.fr/item/MS2_1962__10_165791/