[1] Yunnan Univ Finance & Econ, Sch Finance, Kunming 650221, Peoples R China
[2] Univ Antonio Nebrija, Nebrija, Spain
[3] Qingdao Univ, Sch Econ, Qingdao, Peoples R China
[4] Qingdao Univ, Sch Marxism, Qingdao, Peoples R China
[5] West Univ Timisoara, Fac Econ, Doctoral Sch Econ & Business Adm, Timisoara, Romania
[6] West Univ Timisoara, Finance Dept, Timisoara, Romania
[7] 78 Kedazhi Rd, Qingdao, Shandong, Peoples R China