1. Ordinary and Delay Differential Equations;Driver,1977
2. An Variational Iteration Method For Nonlinearity and Its Applications (in Chinese);He;Mechanics and Application,1998
3. General Use of the Lagrange Multiplier in Nonlinear Mathematical Physics;Inokuti,1978
4. The Method of Weighted Residuals and Variational Principles;Finlayson,1972