1. Characteristics of optic disc in healthy school children;Erkkilä;Acta ophthal. (Kbh.),1979
2. Die Kurzsichtigkeit in Coburger Schulen;Florschütz;Jber. Leist. Ophthal.,1880
3. Occurrence of squint;Frandsen;Acta ophthal. (Kbh.),1960
4. On the etiology of myopia. An etiological study;Goldschmidt;Acta ophthal. (Kbh.),1968
5. Vision anomalies of school children;Hamilton;Amer. J. Ophthal.,1974