S. S. Jagtap, “Systems Evaluation of Subsonic Hybrid-Electric Propulsion Concepts for NASA N+3 Goals and Conceptual Aircraft Sizing”, Int. J. Automot. Mech. Eng., vol. 16, no. 4, pp. 7259–7286, Dec. 2019, doi: 10.15282/ijame.16.4.2019.07.0541.