Volume 13, Issue 7, July 2012, Pages 3219-3222
Volume 12, Issue 10, October 2011, Pages 2679-2683
Volume 12, Issue 5, May 2011, Pages 1161-1166
Volume 10, Issue 4, April 2009, Pages 661-664
Volume 9, Issue 4, April 2008, Pages 771-775