"Controversy over the Metro" (in Brazilian Portuguese). Folha de S.Paulo, year LI, edition 15502, page 20/ republished by the National Library-Brazilian Digital Hemerotheca. November 25, 1971. Retrieved November 27, 2019.
"Infraestrutura"(PDF). Portal de transparência e governança corporativa da Companhia do Metropolitano de São Paulo. November 2019. Retrieved January 3, 2020.
Government of Sao Paulo State (30 January 2010). "Serra inaugura estação Sacomã do Metrô" [Governor Serra opens Metro station Sacoma] (in Brazilian Portuguese). Retrieved 25 December 2019.