1. Text-book of Ophthalmology;BIRCH-HIRSCHFELD, A.;v. Graefes Arch. Ophthal,1904
2. FLYNN, J. A. F. (1952). Trans. ophthal. Soc. Aust., 12, 7.
3. KNUDTZON, K. (1948). Acta ophthal. (Kbh.), 26, 469.
4. Personal communication of extracts from thesis "Macular Lesions";MALIK, S.R.K.,1957
5. NIRANKARI, M. S. (1954). Trans. ophthal. Soc. U.K., 74, 276.