D. Montezzo, A. C. Lages, C. J. Terra Criollo, M. Veloso, R. R. Britto, and V. F. Parreira, “Relationship between maximum mean pressure and peak pressure obtained by digital manometer during maximal respiratory pressure”, J Resp Cardiov Phys Ther, vol. 1, no. 1, pp. 9–15, Apr. 2012.