|   [1] Nayfcn, A.H., Perturbation Methods, John Wiley, New York, Ch.3 (1973). 
[2] Wasow, W.A., On the convergence of an approximation method of M.J.Lighthill, J.Rational Mech.Anal., 4 (1955), 751-767. 
[3] Usher, P.D., Necessary conditions for applicability of Poincar-Lighthill perturbation theory, Quart.Appl.Math., 28 (1971), 463-471. 
[4] Comstock, C., On Lighthill's method of strained coordinates, SIAM J.Appl.Math., 16 (1968), 596-602. 
[5] Pritulo, M.F., On the determination of uniformly accurate solutions of differential equations by the method of perturbation of coordinates, J.Appl.Math.Mech., 26 (1962) .661-667. 
[6] Usher, P.D., Coordinate stretching and interface, location Ⅱ, a new PL expansion, J.Computational Phys., 29, 3 (1978), 29-39. 
[7] Jordan, D.W.and P.Smith.Nonlinear Ordinary Differential Equations, Clarendon Press, Oxford (1977), 152-155.  |