GUIMARÃES, Aldo Marçal et al. Development of a portable prototype: pH meter for prolonged esophageal pH monitoring with low cost materials. International Journal of Advanced Engineering Research and Science, [S. l.], v. 7, n. 4, 2020. Disponível em: https://journal-repository.com/index.php/ijaers/article/view/1832.. Acesso em: 22 jul. 2024.