The Effect Of The Addition of Copper DB Killer On Yamaha Vixion 150cc Motorcycle on Exhaust Emissions: Pengaruh Penambahan DB Killer Tembaga Pada Knalpot Racing Motor Yamaha Vixion 150cc Terhadap Emisi Gas Buang. PELS 2023, 4. https://doi.org/10.21070/pels.v4i0.1423.