1. "Leis da lógica dialética." N.p.:, undated

1. "Leis da lógica dialética." N.p.:, undated, Box: 27, Folder: 5. 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/375913 Accessed September 26, 2026.