Po-Wen Hsieh, Yin-Tzer Shih, Suh-Yuh Yang and Cheng-Shu You. (2018). A Novel Technique for Constructing Difference Schemes for Systems of Singularly Perturbed Equations. Communications in Computational Physics. 19 (5). 1287-1301. doi:10.4208/cicp.scpde14.21s