MUHLY, Paul S.; WILLIAMS, Dana P. Continuous Trace Groupoid $C^*$-Algebras, II. Mathematica Scandinavica, Berkeley, CA, United States, v. 70, p. 127–145, 1992. DOI: 10.7146/math.scand.a-12390. Disponível em: https://journals.msp.org/mscand/article/view/1262. Acesso em: 24 jul. 2026.