. 2009 Dec 23;10:118. doi: 10.1186/1745-6215-10-118
Copyright ©2009 Moergel 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.
Definition of the cervival levels as defined by Robbins 1991.