KOLBERG, O. Congruences for the Coefficients of the Modular Invariant $j(\tau)$. MATHEMATICA SCANDINAVICA, [S. l.], v. 10, p. 173–181, 1962. DOI: 10.7146/math.scand.a-10525. Disponível em: https://www.mscand.dk/article/view/10525. Acesso em: 6 may. 2024.