1. Prevalence of ectopic eruption of the maxillary first permanent molar;Bjerklin;Swed. Dent. J.,1981
2. Ectopic eruption of the first permanent molar;Young;J. Dent. Child.,1957
3. Ectopic eruption pattern in selected permanent teeth;O'Meara;J. Dent. Res.,1962
4. Impaction of permanent first molar with resorption and space loss in region of deciduous second molar;Cheyne;J. Am. Dent. Assoc.,1947
5. The etiology and prevalence of ectopic eruption of the maxillary first permanent molar;Pulver;J. Dent. Child.,1968