1. Eugene Wolff’s anatomy of the eye and orbit;Warwick,1976
2. The anatomy of the limbus;Van Buskirk;Eye,1989
3. A clinical study on central and peripheral corneal thickness;Martola;Arch Ophthalmol,1968
4. The cornea;Pepose,1992
5. The effect of age on human corneal thickness. Statistical implications of power analysis;Siu;Acta Ophthalmol (Copenh),1993