Almamoury, Q. A. (2026) “Ultra-Efficient Hybrid Propulsion System Integrating Stirling Engines and PEM Fuel Cells: Thermodynamic Feasibility and Techno-Economic Assessment”, Vital Annex: International Journal of Novel Research in Advanced Sciences (2751-756X), 5(3), pp. 159–165. Available at: https://journals.innoscie.com/index.php/ijnras/article/view/381 (Accessed: 1 October 2026).