Volume 13, Issue 2, February 2012, Pages 563-567
Volume 13, Issue 1, January 2012, Pages 81-85
Volume 12, Issue 11, November 2011, Pages 2951-2957
Volume 12, Issue 10, October 2011, Pages 2797-2800
Volume 12, Issue 1, January 2011, Pages 99-102
Volume 10, Issue 6, June 2009, Pages 1147-1150