Ashraf, H., Dianat, O., Hajrezai, R., Paymanpour, P., & Azadnia, S. (2014). Endodontic Treatment of a Double-Rooted Maxillary Second Molar with Four Canals: A Case Report. Iranian Endodontic Journal, 9(4), 304–306. https://doi.org/10.22037/iej.v9i4.6404