. 2003 Apr 17;1:9. doi: 10.1186/1477-7525-1-9
Copyright © 2003 Moody and McMillan; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.
Figure 1.
