M. Aminsobhani, N. Shokouhinejad, S. Ghabraei, B. Bolhari, and A. Ghorbanzadeh, “Retreatment of a 6-Canalled Mandibular First Molar with Four Mesial Canals: A Case Report”, Iran Endod J, vol. 5, no. 3, pp. 138–140, Oct. 2010.