Kim, C.-G.
Liang, Z.-P.
Shi, J.-P.
Funding for this research was provided by:
National Research Foundation of Korea (NRF-2011-357-C00006)
National Natural Science Foundation of China (11071149, 11101250)
Directorate for Mathematical and Physical Sciences (1022648, 1313243)
Article History
Received: 25 November 2014
Revised: 18 July 2015
First Online: 9 September 2015