3. "Viva os cem anos do 1o de maio." N.p.:, 1986 May 1.

3. "Viva os cem anos do 1o de maio." N.p.:, 1986 May 1., Box: 28. Eduardo Sarno Collection of Leftist Movements in Brazil, 2002-03. Benson Latin American Collection, The University of Texas at Austin. https://archives.lib.utexas.edu/repositories/4/archival_objects/376019 Accessed September 26, 2026.