RAVNBORG, L; THOMSEN K. Acanthosis nigricans and bile duct malignancy. Acta Dermato-Venereologica, [S. l.], v. 73, n. 5, p. 378–379, 1993. DOI: 10.2340/0001555573378379. Disponível em: https://medicaljournalssweden.se/actadv/article/view/16556. Acesso em: 28 apr. 2026.