DIRDAL, Gunnar. Asymptotic Formulae for the Coefficients of a Class of Modular Forms. Mathematica Scandinavica, Berkeley, CA, United States, v. 31, p. 237–247, 1972. DOI: 10.7146/math.scand.a-11430. Disponível em: https://journals.msp.org/mscand/article/view/2214. Acesso em: 25 jul. 2026.