. 2012 Dec 17;3:8. doi: 10.1186/2041-1480-3-8
Copyright © 2012 Mikroyannidi 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.
Tree showing possible variable replacements.