1. Ahmed, K., 1994. Renewable energy Technologies: A Review of the Status and Costs of Selected Technologies. World Bank Technical Paper No. 240, Energy Series.
2. Alnatheer, O., 2002. Initial Application of Integrated Resource Planning (IRP) in the Kingdom of Saudi Arabia.
3. Review of Historical and Modern Utilization of Wind Power, Wind Energy & Atmospheric Physics Department;Andersen,1997
4. California Public Utilities Commission, 1991. Decision 91-06-022-5 June.
5. De La Quill, P., Kearney, D., Geyer, M., Diver, R., 1993. Solar thermal electric technology. In: Johansson, T., Kelly, H., Reddy, A., Williams, R. (Eds.), Renewable Energy: Sources for Fuels and Electricity. Island Press.