1. Conical cornea in identical twins;Etzine;S Afr Med J,1954
2. Two pairs of identical twins concordant for keratoconus;Franceschetti;Klin Monatsbl Augenheilkd,1958
3. Keratoconus and related noninflammatory corneal thinning disorders;Krachmer;Surv Ophthalmol,1984
4. [A recent case of keratoconus in univitelline twins];Woillez;Bull Soc Ophthalmol Fr,1976
5. Keratoconus in monozygotic twins in New Zealand;Owens;Clin Exp Optometry,1995