JOHANSEN, Torben Bygballe. Convergence of derivations on nearest algebras. Mathematica Scandinavica, Berkeley, CA, United States, v. 58, p. 46–54, 1986. DOI: 10.7146/math.scand.a-12128. Disponível em: https://journals.msp.org/mscand/article/view/1503. Acesso em: 25 jul. 2026.