Reich, Steffen
Burgard, Matthias
Langner, Markus
Jiang, Shaohua
Wang, Xueqin
Agarwal, Seema
Ding, Bin
Yu, Jianyong
Greiner, Andreas
Article History
Received: 7 September 2017
Revised: 4 November 2017
Accepted: 23 November 2017
First Online: 14 February 2018
Competing interests
: The authors declare no competing financial interests.