1. Department of Otolaryngology, Rothschild University Hospital, Haifa. Israel.
2. Department of Otolaryngology, Rothschild University Hospital, Haifa, Israel, from the Medical School at Kaunas, Lithuanian S.S.R.
3. Department of Otolaryngology, Rothschild University Hospital, Haifa, Israel.
4. Rothschild University Hospital, Haifa, Israel.
5. Department of Otolaryngology, Rothschild University Hospital, Haifa, Israel, from Leningrad.