机构:
Beijing Normal Univ, Lab Math & Complex Syst, Minist Educ, Sch Math Sci, Beijing 100875, Peoples R China
Univ Jyvaskyla, Dept Math & Stat, FI-40014 Jyvaskyla, FinlandBeijing Normal Univ, Lab Math & Complex Syst, Minist Educ, Sch Math Sci, Beijing 100875, Peoples R China