@article{1183555725, author = {Pizer, Arnold K.}, title = {Ramanujan graphs and Hecke operators}, journal = {Bull. Amer. Math. Soc. (N.S.)}, volume = {23}, number = {1}, year = {1990}, pages = { 127-137}, language = {en}, url = {http://dml.mathdoc.fr/item/1183555725} }
Pizer, Arnold K. Ramanujan graphs and Hecke operators. Bull. Amer. Math. Soc. (N.S.), Tome 23 (1990) no. 1, pp. 127-137. http://gdmltest.u-ga.fr/item/1183555725/