. 2013 Jan 19;13:7. doi: 10.1186/1471-2288-13-7
Copyright ©2013 Wells et al.; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Figure 1.
Review process for systematic reviews.