“in-Vitro Evaluation of Effect of Smear Layer Removal With ER -YAG & XP Endo Finisher File System on the Quality of Apical Sealing of Root Canals ”. Journal of Hama University , vol. 2, no. 13, Feb. 2020, https://hama-univ.edu.sy/ojs/index.php/huj/article/view/302.