KARLSSON, Per W. Regions of Convergence for Hypergeometric Series in Three Variables. Mathematica Scandinavica, Berkeley, CA, United States, v. 34, p. 241–248, 1974. DOI: 10.7146/math.scand.a-11526. Disponível em: https://journals.msp.org/mscand/article/view/2121. Acesso em: 25 jul. 2026.