6. Wangyang Fu, Shengyong Qin, Lei Liu, Tae-Hwan Kim, Sondra Hellstrom, Wenlong Wang, Wenjie Liang, Xuedong Bai, An-Ping Li, and Enge Wang,Ferroelectric Gated Electrical Transport in CdS Nanotetrapods, NANO LETTERS 11, 1913 (2011).