BIRKELAND, Bent. A Cauchy Problem fo Analytic Functionals. Mathematica Scandinavica, Berkeley, CA, United States, v. 33, p. 130–138, 1973. DOI: 10.7146/math.scand.a-11478. Disponível em: https://journals.msp.org/mscand/article/view/2191. Acesso em: 25 jul. 2026.