Nabil Tawfik El-dabe; Mohamed Yahya Abou-zeid; Ola S. Ahmed. Motion of AThin Film of AFourth Grade Nanofluid With Heat Transfer Down a Vertical Cylinder: Homotopy Perturbation Method Application. J. Adv. Res. Fluid Mech. Therm. Sc. 2024, 66, 101-113.