STØRMER, Erling. Extension of positive maps. Mathematica Scandinavica, Berkeley, CA, United States, v. 126, n. 2, p. 256–258, 2020. DOI: 10.7146/math.scand.a-115974. Disponível em: https://journals.msp.org/mscand/article/view/199. Acesso em: 24 jul. 2026.