5. Costa, Célio. "A nossa luta e o nosso espírito."

5. Costa, Célio. "A nossa luta e o nosso espírito.", Box: 3. 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/371715 Accessed September 27, 2026.