. 2008 Feb 21;2:18–23. doi: 10.2174/1874210600802010018
2008 Bentham Science Publishers Ltd.
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.5/), which permits unrestrictive use, distribution, and reproduction in any medium, provided the original work is properly cited.