9. Kaihui Liu, J.Deslippe, Fajun Xiao, Rodrigo B.Capaz, Xiaoping Hong, S.Aloni, A. Zettl, Wenlong Wang, Xuedong Bai, SG.Louie, Enge Wang, and Feng Wang, An atlas of carbon nanotube optical transitions, NATURE NANOTECHNOLOGY 7, 325 (2012).