1. Ann;BOLLACK, J.;Oculist; Brit,1924
2. System of Ophthalmology;DUKE-ELDER, S.,1961
3. Amer;Kimpton, London E.W.I.N.G.; E, A.;J. Ophthal,1909
4. FOX, S. A. (1947) Ibid., 30, 878
5. MILDER, B., and DEMOREST, B. H. (1954) A.M.A. Arch. Ophthal., 51, i8o