. 2018 Oct 1;31(4):268–276. doi: 10.3344/kjp.2018.31.4.268
Copyright © The Korean Pain Society, 2018
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.