1. Mathematics Department, College of Science, King Saud University, Riyadh 11989, Saudi Arabia
2. Faculty of Mathematics and Computer Science, Babeş-Bolyai University, 400084 Cluj-Napoca, Romania
3. Department of Mathematics, Amity University Rajasthan, NH-11C, Jaipur 302002, India
4. Department of Mathematics and Statistics, College of Science, Al-Imam Mohammad Ibn Saud Islamic University (IMSIU), P.O. Box 65892, Riyadh 11566, Saudi Arabia