FJELDSTAD, Jonas Ekman. An Equation of Finite Differences, which has Some Connection with the Jacobian Thetafunctions. Mathematica Scandinavica, Berkeley, CA, United States, v. 22, p. 81–86, 1968. DOI: 10.7146/math.scand.a-10873. Disponível em: https://journals.msp.org/mscand/article/view/2430. Acesso em: 25 jul. 2026.