. 2004 Aug 6;4:12. doi: 10.1186/1472-6920-4-12
Copyright © 2004 Schultz 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 5.
Training level and site characteristics