@article{GDZPPN002402874, title = {Density of Finite Simple Group Orders.}, journal = {Mathematische Zeitschrift}, volume = {105}, year = {1968}, pages = {175-177}, zbl = {0159.31103}, url = {http://dml.mathdoc.fr/item/GDZPPN002402874} }
Dornhoff, L.; Spitznagel, E.L. Density of Finite Simple Group Orders.. Mathematische Zeitschrift, Tome 105 (1968) pp. 175-177. http://gdmltest.u-ga.fr/item/GDZPPN002402874/