1. Ascher, K. W. Klin. Mbl. Augenheilk.91, 208 (1933).
2. Beselin, O. Klin. Mbl. Augenheilk.73, 691 (1924 II).
3. Bjerke, K. Graefes Arch.53, 511 (1901);55, 191, 389 (1903).
4. Busacea, A. Osp. Bergamo1, 297 (1932); ref. Zbl. Ophthalm.30, 205.
5. Czellitzer Klin. Mbl. Augenheilk.79, 301 (1927).