Jennifer Conrad Seidel, ed. (2011). Answer book: 10,001 fast facts about our world. Washington, D.C.: National Geographic Society. ISBN978-1-4262-0892-8. OCLC751743206.
Machado, Maria Helena P. T. (2011). "Slavery and Social Movements in Nineteenth-Century Brazil: Slave Strategies and Abolition in São Paulo". Review (Fernand Braudel Center). 34 (1/2): 163–191. ISSN0147-9032.