Zhao, Juanying
Chremmos, Ioannis D.
Song, Daohong
Christodoulides, Demetrios N.
Efremidis, Nikolaos K.
Chen, Zhigang
Article History
Received: 24 March 2015
Accepted: 12 June 2015
First Online: 13 July 2015
Competing interests
: The authors declare no competing financial interests.