Carvalho, R., F. Branquinho, J. Sousa Ramos, J. E. Carrasquinho, R. Theias, J. Calado, F. Ferrito, C. . Carmona, and L. Dutschmann. “Pheochromocytoma: 3 Clinical Case Reports”. Internal Medicine, vol. 16, no. 1, Mar. 2009, pp. 43-49, https://revista.spmi.pt/index.php/rpmi/article/view/1385.