Villavicencio-Villavicencio, N. E., & Álvarez-Álvarez, D. P. (2020). Relation between the oral hygiene index and periodontal index in 12-year-old schools in the parish Gil Ramirez Cuenca-Ecuador 2016 . CEUS Scientific Journa, 2(3), 17-22. https://ceus.ucacue.edu.ec/index.php/ceus/article/view/44