Johnson, M., Kavitha, K., Chalishajar, D., Malik, M., Vijayakumar, V., & Shukla, A. (2023). An analysis of approximate controllability for Hilfer fractional delay differential equations of Sobolev type without uniqueness. Nonlinear Analysis: Modelling and Control, 28(4), 632-654. https://doi.org/10.15388/namc.2023.28.32118