TY - JOUR TI - A short review on approximate analytical methods for non-linear problems AU - Tian Yi AU - Feng Guang-Qing JN - Thermal Science PY - 2022 VL - 26 IS - 3 SP - 2607 EP - 2618 PT - Article AB - In this paper, some approximate analytical methods are reviewed, including the variational iteration method and the homotopy perturbation method. Based on the ideas of the two methods, a new method for solving a class of system of Fredholm integral equations of the second kind is proposed. Some examples are given to show the simple solution process and the accuracy of the solution for each method. The emphasis of this review paper focuses on Ji-Huan He's unapproachable ideas and the mathematics beauty, so the references are not exhaustive.