1. Central Intelligence Agency: The world fact book,
https://www.cia.gov/library/publications/the-world-factbook/geos/br.html
2. National Association of Public Transport of Rails,
www.anptrilhos.org.br
3. National Agency of Land Transport: Annual Report, 5th edn., vol. 9. ANTT, Brasilia (2009)
4. Brazilian Association of Companies for Road Passenger Transport,
http://www.abrati.org.br/page/11728
5. National Association of Public Transport: Relatório comparativo 2003-2011 (2012)