Sun, Dali
Fang, Mei
Xu, Xiaoshan
Jiang, Lu
Guo, Hangwen
Wang, Yanmei
Yang, Wenting
Yin, Lifeng
Snijders, Paul C.
Ward, T. Z.
Gai, Zheng
Zhang, X.-G.
Lee, Ho Nyung
Shen, Jian
Article History
Received: 11 February 2013
Accepted: 13 June 2014
First Online: 10 July 2014
Competing interests
: The authors declare no competing financial interests.