KUMJIAN, A. Preliminary algebras arising from local homeomorphisms. MATHEMATICA SCANDINAVICA, [S. l.], v. 52, p. 269–278, 1983. DOI: 10.7146/math.scand.a-12006. Disponível em: https://www.mscand.dk/article/view/12006. Acesso em: 2 may. 2024.