1. National Standardization Agency of Indonesia, SNI 8019:2014. “High pressure biogas quality standard”, BSN, 2014.
2. Ministry of Energy and Mineral Resources. “Decree of the director general of oil and gas No. 116.K/10/DJM/2020 regarding Quality Standards of Specifications for Liquefied Petroleum Gas Types of Fuel Gas that are Marketed Domestically”, 2020
3. American Standard and Testing Methods International, ASTM D1945 - 14(2019). “Standard Test Method for Analysis of Natural Gas by Gas Chromatography”, ASTM, 2019.
4. International organization for standardization, ISO 14687:2019. “Hydrogen fuel quality — Product specification”, ISO, 2019
5. Ministry of Environment and Forestry, Minister of Environment and Forestry Regulation No. P.14/MENLHK/SETJEN/KUM.1/7/2020. “The Air Pollutant Standard Index”, 2020.