Multiplicative characteristics of function for the number of classes of primitive hyperbolic elements in the group $\Gamma_0(N)$ by level $N$
V. V. Golovchanskii, M. N. Smotrov

This publication is cited in the following articles:

1. V. V. Golovchanskii, M. N. Smotrov, “On the spectrum of the Laplace–Beltrami operator for congruence subgroups of the modular group”, St. Petersburg Math. J., 23:4 (2012), 659–664