Voir la notice de l'article provenant de la source Novi sad journal of mathematics website
@article{NSJOM_2009_39_2a_10, author = {R. Shen}, title = {A new characterization of $PSL_2(7)$}, journal = {Novi Sad Journal of Mathematics}, pages = {97-101}, publisher = {mathdoc}, volume = {39}, number = {2}, year = {2009}, url = {http://geodesic.mathdoc.fr/item/NSJOM_2009_39_2a_10/} }
R. Shen. A new characterization of $PSL_2(7)$. Novi Sad Journal of Mathematics, Tome 39 (2009) no. 2. http://geodesic.mathdoc.fr/item/NSJOM_2009_39_2a_10/