M. A. Badr and  M.N. El Kordy and  A. N. Mohib and  M. M. Ibrahim,  Cost Analysis of Hybrid Wind Energy Generating System Considering CO2 Emissions .   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2016, vol. 113(5). 552 - 559
    [viewed 14 October 2019]. Available from: https://publications.waset.org/pdf/10004421.