Nadjafi, Jafar, and Fahimeh Akhavan Ghassabzade. “The Numerical Solution of the Singularly Perturbed Differential-Difference Equations Based on the Meshless Method”. International Journal of Applied Mathematical Research, vol. 3, no. 2, Mar. 2014, pp. 116-21, https://doi.org/10.14419/ijamr.v3i2.1595.