[1] Quaid I Azam Univ, Dept Math, Islamabad 44000, Pakistan
[2] Ton Duc Thang Univ, Math & Its Applicat Life Sci Res Grp, Ho Chi Minh City, Vietnam
[3] Ton Duc Thang Univ, Fac Math & Stat, Ho Chi Minh City, Vietnam
[4] HITEC Univ, Rawalpindi 47080, Punjab, Pakistan
[5] Pakistan Inst Nucl Sci & Technol PINSTECH, Hlth Phys Div, Islamabad, Pakistan