1. Division of Mathematics, Department of Sciences and Humanities, Vignan's Foundation for Science, Technology and Research, Vadlamudi, Andhra Pradesh - 522213, India.,
2. Department of Mathematics, Acharya Nagarjuna University Ongole Campus, Ongole, Andhra Pradesh -523001, India,,
3. Department of Mathematics, Sri Vasavi Institute of Engineering and Technology, Nandamuru, Krishna Dt, A.P. – 521369