@article{05909775, title = {Introduction to sporadic groups.}, journal = {SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]}, volume = {7}, year = {2011}, doi = {10.3842/SIGMA.2011.009}, zbl = {1219.20016}, language = {en}, url = {http://dml.mathdoc.fr/item/05909775} }
Boya, Luis J. Introduction to sporadic groups.. SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only], Tome 7 (2011) . doi : 10.3842/SIGMA.2011.009. http://gdmltest.u-ga.fr/item/05909775/