Carvalhinhos, A., Freire, A., Novais, L., Urceira Lopes, M. J., Veloso, J., & Pinto Correia, J. (1986). Contribution of manometry of the esophagus in clinical medicine. Acta Médica Portuguesa, 7(1), 15–23. https://doi.org/10.20344/amp.3588