Batutah, Moh Arif and Ariani, Betty and Kusnanto, Hadi and Sofana, Ilyas and Syahrir, Irwan Variasi Busi terhadap Analisa Performa Mesin 4 Langkah Spark Plug Variations On 4-Stroke Engine Performance Analysis. J-Proteksion: Jurnal Kajian Ilmiah dan Teknologi Teknik Mesin, 8 (2). pp. 123-127.