. 2014 Jun 16;15(1):40. doi: 10.1186/1129-2377-15-40
Copyright © 2014 Dong et al.; licensee Springer.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.
Figure 1.
The development process of headache knowledge.