D. Vivek, K. Kanagarajan, and S. Harikrishnan, “Theory and Analysis of Impulsive Type Pantograph Equations with Katugampola Fractional Derivative”, JVTSD, vol. 2, no. 1, pp. 9–20, Mar. 2018, doi: 10.5890/JVTSD.2018.03.002.