1. http://www.who.int/fctc/text_download/en/index.html
2. http://www.who.int/tobacco/surveillance/en_tfi_gats_2010_brazil.pdf
3. http://www.ibge.gov.br/english/estatistica/populacao/trabalhoerendimento/pnad2009/default.shtm
4. http://www.who.int/tobacco/resources/publications/tobaccocontrol_handbook/en/