Volume 15, Issue 13, December 2014, Pages 5239-5243
Volume 15, Issue 16, December 2014, Pages 6665-6668
Volume 15, Issue 20, December 2014, Pages 8887-8891
Volume 12, Issue 4, April 2011, Pages 1001-1005
Volume 10, Issue 6, June 2009, Pages 1039-1040