. 2009 Mar 26;2(1):13–19. doi: 10.3342/ceo.2009.2.1.13
Copyright © 2009 Korean Society of Otorhinolaryngology-Head and Neck Surgery
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.