1. BILLSON, F. A. (1973) Trans. ophthal. Soc. N.Z., 25, I69
2. CARTER, R. B. (I887a) Proc. med. Soc. Lond., 10, 290 (I887b) Brain, IO, Ix9 (1889) Brit. med. J., I, 399
3. In "The Optic Nerve";DAVIDSON, s I.;K; s. CANT,1969
4. i65 HAYREH, s. s;GALBRAITH, J.E.K.;Z; Brit,1973
5. Trans;SMITH, J.L.;Amer. Acad. Ophthal., Otolaryng,1958