1. Extreme conical cornea;Jackson;Amer. Jour. Ophth.,1919
2. Keratoconus, etiology and treatment;Knapp;Arch. of Ophth.,1929
3. Report of 3 cases of keratoconus;Török;Arch. of Ophth.,1928
4. Keratoconus treated with galvanocautery;Knapp;Arch. of Ophth.,1892
5. Optical correction of conical cornea with contact glasses;O'Rourke;Amer. Jour. Ophth.,1929