I Wayan Angga Widianta Putra, I. G. K. Sukadana, I Gusti Ngurah Putu Tenaya, and I Putu Widiarta. “The Effect of Types of Biogas and Methanol Purification and Loading As Fuel for Four-Stroke Generators on Exhaust Emissions”. Natural Sciences Engineering and Technology Journal, Vol. 3, no. 2, Mar. 2023, pp. 200-5, doi:10.37275/nasetjournal.v3i2.37.