RAO, N. V. A Note on Tolstov’s Theorem on Harmonic Functions in the Plane. Mathematica Scandinavica, Berkeley, CA, United States, v. 78, p. 178–182, 1996. DOI: 10.7146/math.scand.a-12581. Disponível em: https://journals.msp.org/mscand/article/view/1048. Acesso em: 25 jul. 2026.