1. “EBA's biomethane fact sheet”, European Biogas Association, http://european-biogas.eu/biogas/.
2. prEN 16723-1 – Natural Gas and Biomethane for Use in Transport and Biomethane for Injection in the Natural Gas Network — Part 1: Specifications for Biomethane for Injection in the Natural Gas Network;European Organization for Standardization,2014
3. prEN 16723-2 – Natural Gas and Biomethane for Use in Transport and Biomethane for Injection in the Natural Gas Network — Part 2: Automotive Fuel Specifications;European Organization for Standardization,2014
4. Trace organic compounds in landfill gas at seven U.K. Waste disposal sites;Allen;Environ. Sci. Technol.,1997
5. M. Arnold, Reduction and Monitoring of Biogas Trace Compounds, VTT, Research Notes 2496.