1. Alexander, Herbert B. 1922. Brazilian and United States Slavery Compared. The Journal of Negro History 7 (4): 349–364.
2. Amann, Edmund, Werner Baer, and Donald V. Coes. 2011. Energy, Bio Fuels and Development: Comparing Brazil and the United States. Abingdon: Routledge.
3. Andrade, Renata Marson Teixeira de, and Andrew Miccolis. 2011. Policies and Institutional and Legal Frameworks in the Expansion of Brazilian Biofuels. Report. Center for International Forestry Research.
https://www.jstor.org/stable/resrep02306
4. Araújo, Tânia Bacelar de, and Paulo Simões. 2004. Northeast, Northeasts, What Northeast? Latin American Perspectives 31 (2), Brazilian Northeast: Globalization, Labor, and Poverty: 16–41.
5. Baptista, Emerson Augusto, Guy J. Abel, and Járvis Campos. 2018. Internal Migration in Brazil Using Circular Visualization. Regional Studies, Regional Science 5 (1): 361–364.