. 2012 Jul 25;53(5):1045–1048. doi: 10.3349/ymj.2012.53.5.1045
© Copyright: Yonsei University College of Medicine 2012
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.