. 2009 Feb 17;9:59. doi: 10.1186/1471-2458-9-59
Copyright © 2009 Pasricha 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 2.
Sampling strategy.