16. Yeping Jiang, Yilin Wang, Mu Chen, Zhi Li, Canli Song, Ke He, Lili Wang, Xi Chen, Xucun Ma, Qi-Kun Xue, Landau Quantization and the Thickness Limit of Topological Insulator Thin Films of Sb2Te3, PHYSICAL REVIEW LETTERS 108, 016401 (2012).