1. XIV Concilium Ophthalmologicum Hispania;ARRUGA, H.,1933
2. BARTLEY, W., KREBS, H. A., and O'BRIEN, J. R. P. (1953). Spec. Rep. Ser. med. Res. Coun. (Lond.), No. 280.
3. BouRNE, G. H. (1942). Lancet, 2, 661.
4. CAGIANUT, B., and WUNDERLY, C. (1953). Brit. J. Ophthal., 37, 229. CoNTNo, F. (1941). Ann. Ottal., 69, 321.
5. DE VINCENTIIs, M. (1958). Arch. Ottal., 62, 5.