1. AXENFELD, T. (1911). Klin. Mbl. Augenheilk., 49 (1), 345. CAMPos (1897). Arch. Ophtal., 17, 529.
2. In "Untersuchungen zur Naturlehre des Menschen und der Thiere;CZERMAK, J.,1860
3. ed. J. Moleschott, vol. 7, p. 377.
4. Text-book of Ophthalmology;Roth, Giessen. (Cited Tepliachine, 1894.) DEMTSCHENKO; S.;Diss,1871
5. Roth, Giessen. (Cited by Tepliachine, 1894.) DEMTSCHENKO (1952). Ibid., vol. 5, p. 5209.