2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70857We show that Haefliger's cohomology for etale groupoids, Moore's cohomology for locally compact groups and the Brauer group of a locally compact groupoid are all particular cases of sheaf (or Cech) cohomology for topological simplicial spaces.32 pagesOperator Algebras22A22, 20J06; 55Nxxtext