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2. , and SMOUT, C. F. V. (1938). Ibid., 72, 358.
3. Textbook of the Fundus of the Eye;BALLANTYNE, A.J.; MICHAELSON, I.C.,1962
4. BENSON, A. H. (1882). Trans. ophthal. Soc. U.K., 2, 55.
5. COATS, G. (1914). Ophthalmoscope, 12, 400.