1. Department of Mathematics, The University of Burdwan, Purba Bardhaman, West Bengal, India
2. Department of Mathematics, College of Science and Humanities in Al-Kharj, Prince Sattam bin Abdulaziz University, Al-Kharj, Saudi Arabia + Department of Mathematics and Computer Science, St. Thomas College, Bhilai, Chhattisgarh, India
3. Department of Pharmaceutical Sciences, ”Vasile Goldiş” Western University of Arad, Arad, Romania
4. University of Banja Luka, Faculty of Electrical Engineering, Banja Luka, Bosnia and Herzegovina