1. Evidence from polar ice cores for the increase in atmospheric CO2 in the past two centuries;Neftel;Nature.,1985
2. Tans P NOAA/ESRL. Trends in atmospheric carbon dioxide http://www.esrl.noaa.gov/gmd/ccgg/trends/mlo.html
3. International Energy Agency Key World Energy Statistics 2008 http://iklim.cob.gov.tr/iklim/Files/eKutuphane/Key%20 world%20Energy%20Statistics.pdf
4. Irons R Sekkapan G Panesar R Gibbins J Lucqiuaud M CO 2 capture ready plants. Prepared for IEA greenhouse gas R&D programme http://www.iea.org/publications/freepublications/publica tion/CO2_Capture_Ready_Plants.pdf