Reference
- Bormioli R. Clin. Otorino-Lar. 1953; 5: 313
- Courtade A. Arch, internat. Laryng. 1903; 16: 598–884; 320
- Dibeler V. H., Cordero F. J. of Research of the National Bureau of Standards 1951; 46: 1
- Greenough M. L., Williams W. E. J. of Research of the National Bureau of Standards 1951; 46: 5
- Spiess G. Die Untersuchungsmethode der Nase und ihre Nebenhohlen, Heyman's Handbuch d. Laryng. u. Rhin.3. ed. Wien 1900; Bd. 1
- Stoksted P. Acta oto-laryng. 1953; 109: 159, suppl.
- Stoksted P. Acta oto-laryng. 1956; 46: 64