. 2011 Oct 11;12:221. doi: 10.1186/1745-6215-12-221
Copyright ©2011 Frei 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.
Flow chart.