“Asymptotic Criteria of Neutral Differential Equations With Positive and Negative Coefficients and Impulsive Integral Term”. Iraqi Journal of Science 61, no. 9 (September 29, 2020): 2315–2323. Accessed May 3, 2024. https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/1732.