1. Chang K.W. and F.A. Howes,Nonlinear Singular Perturbation Phenomena. Springer-Verlag Pub (in press)
2. Bernfeld, S. and V. Lakshmckautham, An Introduction to Non-linear Boundary Value Problems, Academic Press, New York (1974).
3. Hebets, P. and M. Laloy, E'tud de problèmes aux limites par la méthod des sur-et soussolutions, Lecture notes, Catholic University of Louvain (1974).
4. Chang, K.W. and G.X.Lin, Boundary and angular layer behavior in singularly perturbed semilinear systems.Appl. Math. and Mech. Vol. 5, No. 3 (1984).
5. Lin Zong-chi, The estimation of singular perturbation boundary value problem for a semilinear system, (in press)