Summary: Ji-Huan He
’s work [Int. J. Nonlinear Sci. Numer. Simul. 2, No. 3, 257–264 (2001; Zbl 1072.34508
); Int. J. Non-Linear Mech. 37, No. 2, 309–314 (2002; Zbl 1116.34320
)] on asymptotic techniques is briefly reviewed, and his parameter-expanding methods including the modified Lindstedt-Poincare method and the bookkeeping parameter method are discussed in detail. Some remarkable virtues of the methods are exploited, and their applications are illustrated.