1. Department of Mathematics, Taki Government College, Taki 743429, West Bengal, India
2. Department of Applied Mathematics, University Politehnica of Bucharest, 060042 Bucharest, Romania
3. Academy of Romanian Scientists, 54 Splaiul Independentei, 050094 Bucharest, Romania
4. Fundamental Sciences Applied in Engineering-Research Center (SFAI), University Politehnica of Bucharest, 060042 Bucharest, Romania
5. Department of Mathematics, COMSATS University Islamabad, Islamabad 44000, Pakistan