@article{DAN_1978_242_1_a8,
     author = {N. V. Kuznetsov},
     title = {The distribution of norms of primitive hyperbolic classes of the modular group and asymptotic formulas for the eigenvalues 
},
     journal = {Doklady Akademii Nauk},
     pages = {40--43},
     publisher = {mathdoc},
     volume = {242},
     number = {1},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1978_242_1_a8/}
}