@article{DAN_1977_233_6_a1,
     author = {A. B. Venkov},
     title = {On an asymptotic formula connected with the number of eigenvalues corresponding to odd eigenfunctions of the {Laplace--Beltrami} operator on a fundamental region of the modular group $\mathrm{PSL}(2,\mathbf{Z})$},
     journal = {Doklady Akademii Nauk},
     pages = {1021--1023},
     publisher = {mathdoc},
     volume = {233},
     number = {6},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_233_6_a1/}
}