. 2010 Jul 15;51(5):648–652. doi: 10.3349/ymj.2010.51.5.648
© Copyright: Yonsei University College of Medicine 2010
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 noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.