Clavero, Carmelo, et al. “Schemes Convergent ε-Uniformly for Parabolic Singularly Perturbed Problems With a Degenerating Convective Term and a Discontinuous Source”. Mathematical Modelling and Analysis, vol. 20, no. 5, Sept. 2015, pp. 641-57, https://doi.org/10.3846/13926292.2015.1091041.