Zhang, Fang
Sun, Fengzhu
Luan, Yihui
Funding for this research was provided by:
National Natural Science Foundation of China (11371227)
National Natural Science Foundation of China (61432010)
National Natural Science Foundation of China (11626247)
Division of Mathematical Sciences (1518001)
Article History
Received: 12 December 2017
Accepted: 3 January 2019
First Online: 28 January 2019
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