Piekarski, Daniel John, James H. Lee, Robert D. Garrick, Andrew Smith, Kenneth E. Krapf, and John Bulzacchelli. “Study of the Performance and Emissions of a Methane Fueled V-Twin Four Stroke Spark Ignited Engine”. Newest Updates in Physical Science Research Vol. 15 (August 24, 2021): 133–144. Accessed June 4, 2026. https://stm.bookpi.org/NUPSR-V15/article/view/3484.