Alves, J., A. . Panarra, F. Soromenho, and M. Vaz Riscado. “Nail Fold Capilaroscopy in Autoimmune Diseases”. Internal Medicine, vol. 5, no. 1, Mar. 1998, pp. 16-22, https://revista.spmi.pt/index.php/rpmi/article/view/2101.