1. Department of Mathematics , Prasad V Potluri Siddhartha Institute of Technology Vijayawada-520007, Andhra Pradesh , India
2. Department of Mathematics , Vallurupalli Nageswara Rao Vignana Jyothi Institute of Engineering and Technology (VNR VJIET) Bachupaly, Hyderabad-500090 , India
3. Department of Aeronautics and Astronautics , Air Force Institute of Technology , Wright Patterson Air Force Base Dayton, Ohio 45433, USA