1. Hypodontia in the permanent dentition;Grahnen;Odontol. Revy,1956
2. The relationship between maternal age and parity, birth weight and hypodontia in naval recruits;Keene;J. Dent. Child.,1966
3. Zahnunterzahl bei Zwillingen;Zeiger;Paradentium,1931
4. Oral Pathology;Zeiger,1960
5. Congenitally missing tooth in one of identical twins;Tanner;J. Am. Dent. Assoc.,1955