ERIN K. PURDY-PAYNE; LARRY B. MELLICK. Understanding Headaches Classification. Emergency Medicine, [S. l.], v. 4, n. 1, p. 1–4, 2018. DOI: 10.17140/EMOJ-4-146. Disponível em: https://openventio.us/index.php/EM/article/view/1916. Acesso em: 24 oct. 2026.