Sasikumar, Raman, and Velusamy Vijayakumar. “Approximate Controllability of Second-Order Impulsive Integro-Differential Systems Involving State-Dependent Delay and Damping Effects via Resolvent Operator”. Nonlinear Analysis: Modelling and Control, vol. 31, June 2026, pp. 1-20, https://doi.org/10.15388/namc.2026.31.47459.