1. Eggston, A. A., and Wolff, D., “Histopathology of the ear, nose and throat” 1947, published by the William and Wilkin’s comp. Baltimore.
2. Hejek, F. ven, quoted by Eggston and Wolff, Ref. No. 1.
3. Putschkowsky, A., quoted by by Eggston and Wolff, Ref. No.
4. Lillie, R. D., Histopathologic Technic, 1948, The Blackiston Company Philadelphia and Toronto.