Luo, Tao
Xin, Zhouping
Zeng, Huihui
Funding for this research was provided by:
Division of Mathematical Sciences (1408839, CUHK-4048/13P)
Research Grants Council, University Grants Committee, Hong Kong
National Natural Science Foundation of China (11301293)
Article History
Received: 19 July 2015
Accepted: 22 July 2016
First Online: 17 September 2016