Lungu, Joseph, Lennox Siwale, and Edwin Luwaya. “Study and Effect of Ignition Timing on the Combustion Characteristics of Gasoline En 91 in a Spark Ignition Engine”. New Approaches in Engineering Research Vol. 1 (June 24, 2021): 104–124. Accessed June 4, 2026. https://stm.bookpi.org/NAER-V1/article/view/1914.