Supratim Das, On the Renormalization Group Techniques for the Cubic-Quintic Duffing Equation, IFSL Volume 10, International Frontier Science Letters (Volume 10) https://www.scipress.com/IFSL.10.1 Abstract: We apply the renormalization group techniques for solving the nonlinear cubic-quintic Duffing equation in the presence of an external periodic, non-autonomous force with an additional damping term. We also make a comparative study with the multiple-time scale approach and show that the correction to the frequency is the same. Keywords: Duffing Oscillator, Indicial Term, Multiple Time Scales, Renormalization Group