International Energy Agency, Organisation for Economic Co-operation and Development, & ProQuest (Firm). (2008). Natural gas information: With 2007 data. OECD/IEA.
Chicago-viite (17. p.)International Energy Agency, Organisation for Economic Co-operation and Development, ja ProQuest (Firm). Natural Gas Information: With 2007 Data. Paris: OECD/IEA, 2008.
MLA-viite (9. p.)International Energy Agency, et al. Natural Gas Information: With 2007 Data. OECD/IEA, 2008.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.