1. Leber, Th. In Graefe & Saemisch's Handbuch der gesamten Aughenheilkunde. Ed. 2, Leipzig, W. Engelmann, 1903, v. 2, p. 63 ff.
2. 1b. —. I.e., p. 75.
3. Troncoso, M. U. Klin. M. f. Augenh., 1914, v. S3, p. 10.
4. 2b. —. Amer. Jour. Ophth., 1921, v. 4, p. 323.
5. 2c. —. Amer. Jour. Ophth., 1925, v. 8, p. 438.