PALMSTRØM, Mathias. Exotic groupoid $C^*$-algebras associated to double groupoids. Mathematica Scandinavica, Berkeley, CA, United States, v. 130, n. 3, 2024. DOI: 10.7146/math.scand.a-149438. Disponível em: https://journals.msp.org/mscand/article/view/37. Acesso em: 24 jul. 2026.