GOULD, H. W. The $q$-Series Generalization of a Formula of Sparre Andersen. MATHEMATICA SCANDINAVICA, [S. l.], v. 9, p. 90–94, 1961. DOI: 10.7146/math.scand.a-10626. Disponível em: https://www.mscand.dk/article/view/10626. Acesso em: 2 may. 2024.