Melo, J. B. da C., T. F. Campos, D. A. de Freitas, R. de O. Borja, R. A. do Nascimento, and K. M. P. P. de Mendonça. “Comparison Between Maximal Respiratory Pressures Obtained from Digital and Analog Manovacuometer in Healthy Children”. Journal of Respiratory and CardioVascular Physical Therapy, vol. 1, no. 2, June 2013, pp. 44-50, https://periodicos.ufrn.br/revistadefisioterapia/article/view/3598.