1. ASHTON, N. (1951). Proc. roy. Soc. Med., 44,747.
2. BECKER, B., and POST, L. T. (1951). Amer. J. Ophthal., 34,677.
3. KUWABARA, T., and COGAN, D. G. (1960). A.M.A. Arch. Ophthal., 64, 904.
4. Retinal Circulation in Man and Animals;MICHAELSON, I.C.,1954
5. WOLTER, J. R. (1956). v. Graefes Arch. Ophthal., 158, 235.