SADYKOV, T. M. On the Horn system of partial differential equations and series of hypergeometric type. Mathematica Scandinavica, Berkeley, CA, United States, v. 91, n. 1, p. 127–149, 2002. DOI: 10.7146/math.scand.a-14382. Disponível em: https://journals.msp.org/mscand/article/view/837. Acesso em: 24 jul. 2026.