JOURNAL OF PHYSICS-CONDENSED MATTER, vol. 23, no. 17, page. 175902, 2011-05-04
PHYSICAL REVIEW B, vol. 82, no. 18, page. 184109, 2010-11-15
Journal of Physical Chemistry C, vol. 114, no. 29, page. 12535 - 12544, 2010-07-29