@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/}
}