1. Personal communication;CLEMETT, R.S.; KOHNER, E.M.; HAMILTON, A.M.;Ibid,1973
2. Brit;HILL, D.W.;J. Ophthal,1968
3. KOHNER, E. M., SHILLING, j., and HAMILTON, A. M. (1976) (In press)
4. Acta XVII Concilium Ophthalmologicum, Canada and USA, I954;SMITH, R.;ophthal. Soc. U. K; Trans,1955
5. Trans;WISE, G.N.;Amer. ophthal. Soc,1956