Simões, Ingrid ísis Nogueira, et al. “Comparative Study of Splinted and Unsplinted Implant-Retained Maxillary Overdentures Without Palatal Coverage: A Literature Review”. Brazilian Dental Science, vol. 20, no. 4, Dec. 2017, pp. 32-41, doi:10.14295/bds.2017.v20i4.1482.