1. Austin. J. Smith Annals of Otol. 71:571: 1962.
2. Boyes Korkes F.–Recent advances in otolaryngoloy (P. 227, 1958)
3. Davison F.W. et al. Annals of otol. 72:462: 1965.
4. Eggston A.E. Annals of otol 70:1080: 1961.
5. Karunaratne Abstract from exerpta Medica E.N.T. 11:315: 1958.