Khan A, Ahmed R, Chowdhury SS, Qauder SA. Incidence of four canals in root-canal-treated mandibular first molars in Bangladeshi population. Update Dent. Coll. j [Internet]. 2015 Jul. 9 [cited 2024 Nov. 24];4(2):4-8. Available from: https://banglajol.info/index.php/UpDCJ/article/view/24040