UEDA, Yoshimichi. Remarks on free products with respect to non-tracial states. Mathematica Scandinavica, Berkeley, CA, United States, v. 88, n. 1, p. 111–125, 2001. DOI: 10.7146/math.scand.a-14317. Disponível em: https://journals.msp.org/mscand/article/view/888. Acesso em: 24 jul. 2026.