Jassem sarmad A, Hanoon RM. Effect of Hydrogen Fuel Used in Internal Combustion Engine to Improve the Efficiency of Spark Ignition Engine. Journal of Petroleum Research and Studies [Internet]. 2025Dec.21 [cited 2025Dec.23];15(4):144-6. Available from: https://jprs.gov.iq/index.php/jprs/article/view/983