1. Brit;ASHTON, N.;J. Ophthal,1964
2. Amer;BURKI, E.;Ibid; Arch,1961
3. DUKE, J. R., and DUNN, S. N. (1958) A.M.A. Arch. Ophthal., 59, 204 FREEMAN, A. I., and JOHNSON, W. W. (1968) Cancer Res., 28, 1490
4. FRIEDMAN, N. B., and DRUTZ, E. (1958) Cancer, iI, io6o
5. Arch;GASS, J.D.M.;Ophthal. (Chicago),1964