1. Ramos, J.I.: Exponential methods for singularly-perturbed ordinary differential-difference equations. Appl. Math. Comput. 182, 1528–1541 (2006)
2. Sharma, K.K., Kaushik, A.: A solution of the discrepancy occurs due to using the fitted mesh approach rather than to the fitted operator for solving singularly perturbed differential equations. Appl. Math. Comput. 181, 765–766 (2006)
3. Kadalbajoo, M.K., Devendra, K.: Fitted mesh B spline collocation method for singularly perturbed differential-difference equations with small delay. Appl. Math. Comput. 204, 90–98 (2008)
4. Kadalbajoo, M.K., Sharma, K.K.: A numerical method based on finite difference for boundary value problems for singularly perturbed delay differential equations. Appl. Math. Comput. 197, 692–707 (2008)
5. Pratima, R.: Numerical analysis of singularly perturbed delay differential turning point problem. Appl. Math. Comput. 218, 3483–3498 (2011)