Affiliation: | 1. School of Management Science and Engineering, Nanjing University, Nanjing, 210093, PR China;2. Ibn Zohr University, Presidence, BP 32/S, Agadir, Morocco;3. Mathematics Department, COMSATS Institute of Information Technology, Islamabad, Pakistan;4. School of Economic and Management, Nanjing Forestry University, Nanjing, 210037, PR China |