1. AshakaCem (2007). Official web site of AshakaCem Cement Plc Nigeria. Retrieved November 11, 2007 from http://ashakaCem.Com/lafarge.htm .
2. Batelle (2002). Toward a sustainable cement industry: Climate change management and the cement industry. Retrieved October 18, 2006, from http://www.wbcsd.cement.org/firdreport.asp .
3. Clean Air (2007). Emission control system for today’s air quality standard. Retrieved November 11, 2007 from http://www.epa.gov/air/urbanair/Nox/hlth.html .
4. EIPPC (European Integrated Pollution Prevention and Control Bureau) (2001). Reference document on best available techniques in the cement and lime manufactory industries, Seville.
5. Felix, B. D. (2000). Concept for development national capacity to implement industrial clean development mechanism project in Africa: Nigeria case study. Retrieved November 11, 2007, from www.Unido.Org/file-storage/download/?file-ed=29634 .