Castello Branco, B., and R. M. Rocha. “CURRENT CLINICAL INTERPRETATION OF PPD TEST: AN APPROACH ELUCIDATING”. Revista Brasileira De Ciências Da Saúde, vol. 16, no. 2, May 2012, pp. 249-52, https://periodicos.ufpb.br/ojs/index.php/rbcs/article/view/10803.