1. National Oceanic And Atmospheric Adminstration. Greenhouse Gases, Carbon Dioxide And Methane, Rise Sharply In 2007. InScienceDaily; April 24, 2008; http://www.sciencedaily.com-/releases/2008/04/080423181652.htm(accessed May 12, 2009).
2. U.S. Department of Energy. U.S. Greenhouse Gas Emissions Still Increasing. InScienceDaily; Dec. 5, 2008; http://www.sciencedaily.com/releases-/2008/12/081204093041.htm(accessed May 12, 2009).
3. Tan, R., Corragio, G. and Santos, S.IFRFDoc. No. G 23/y/l.
4. VDZ Research Institute of the Cement Industry and PENTA Engineering Group. Carbon Dioxide Control Technology;Portland Cement Association, PCA R&D SN 3001, 2008.