. 2013 Apr 3;26(2):203–206. doi: 10.3344/kjp.2013.26.2.203
Copyright © The Korean Pain Society, 2013
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.