1 Department of Engineering Mathematics, GITAM University Hyderabad Campus, Rudraram, Patancheru Mandal, Medak Dist.-502 329, A.P. India.
2 Gort Engovation (Aerospace Engineering Sciences), 15 Southmere Avenue, Bradford, BD7 3NU, England, UK.
3 Department of Mathematics, Vidya Jyothi Institute of Technology, Aziz Nagar Gate, C.B. Post, Hyderabad-500075, A.P. India.