letter . 2013 Dec 26;65(6 Suppl):S59–S61. doi: 10.4097/kjae.2013.65.6S.S59
Copyright © the Korean Society of Anesthesiologists, 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.