Margarido, E., M. Mendonça, P. Cardigos, M. Póvoas, and B. Veloso. “Syphilitic Retinitis in Human Immunodeficiency Virus Infection”. Internal Medicine, vol. 3, no. 3, Sept. 1996, pp. 166-8, https://revista.spmi.pt/index.php/rpmi/article/view/2289.