Nugroho, Arif Setyo. “The Effect of Installing Modified Copper in Muffler to Reduce CO Levels in Vehicle Exhaust”. Jurnal E-Komtek (Elektro-Komputer-Teknik) 5, no. 1 (June 29, 2021): 123-132. Accessed November 27, 2021. https://jurnal.politeknik-kebumen.ac.id/E-KOMTEK/article/view/545.