1. Nefedov, N.N. and Nikulin, E.I., Existence and stability of periodic contrast structures in the reactionadvection-diffusion problem, Russian J. Math. Phys., 2015, vol. 22, no. 2, pp. 215–226.
2. Volkov, V.T. and Nefedov, N.N., Development of the asymptotic method of differential inequalities for investigation of periodic contrast structures in reaction-diffusion equations, Comput. Math. Math. Phys., 2006, vol. 46, no. 4, pp. 585–593.
3. Nefedov, N.N., An asymptotic method of differential inequalities for the investigation of periodic contrast structures: Existence, asymptotics, and stability, Differ. Equations, 2000, vol. 36, no. 2, pp. 298–305.
4. Nefedov, N.N., The method of differential inequalities for some classes of nonlinear singularly perturbed problems with internal layers, Differ. Equations, 1995, vol. 31, no. 7, pp. 1077–1085.
5. Vasil’eva, A.B., Butuzov, V.F., and Nefedov, N.N., Contrast structures in singularly perturbed problems, Fund. Prikl. Mat., 1998, vol. 4, no. 3, pp. 799–851.