Venskutonis, Tadas. “Periapical Tissue Evaluation: Analysis of Existing Indexes and Application of Periapical and Endodontic Status Scale (PESS) in Clinical Practice”. Giornale Italiano di Endodonzia 30, no. 1 (1): 14-21. Accessed August 5, 2021. https://giornaleitalianoendodonzia.it/index.php/gie/article/view/44.