1. Department of Mathematics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
2. Department of Mathematics, Khwaja Fareed University of Engineering and Information Technology Rahim Yar Khan, Pakistan
3. Department of Mathematical Sciences, Federal Urdu University of Art, Science and Technology, Islamabad, Pakistan
4. Centre for Advanced Studies in Pure and Applied Mathematics, Bahauddin Zakariya University, Multan, Pakistan