1. Systematisches Handbuch der Zahnheikunde;Carabelli,1844
2. Bemerkungen u ber Wurzelvariationen am menschlichen unteren Molaren;Bolk;Zeiting fur Morphologie Anthropologie,1915
3. Comparison of the characteristics and anomalies of the deciduous and the permanent dentition;Brabant;J Dent Res,1967
4. Anomalies of the primary dentition;Menczer;J Dent Child,1955
5. Three-rooted lower molars in man and their racial distribution;Tratman;Br Dent J,1938