1. Treatment of malocclusion of the teeth;Angle,1907
2. Conjectures and refutations;Popper,1963
3. Clinical epidemiology;Sackett,1991
4. Are random controlled trials appropriate for orthodontics?;Mew;Evid Based Dent,1991
5. The aetiology of irregularity and malocclusion of the teeth;Brash,1956