NATURE, vol. 488, no. 7413, page. 627 - 632, 2012-08-30
Nano Letters, vol. 13, no. 8, page. 3942 - 3946, 2013-08
Nano Letters, vol. 14, no. 10, page. 5706 - 5711, 2014-10
Nano Letters, vol. 13, no. 11, page. 5660 - 5665, 2013-11