F. Amin Salehi and  L. Sharp and  M. A. Abdoli and  D.E.Cotton and  K.Rezapour,  The Necessity of Biomass Application for Developing Combined Heat and Power (CHP)with Biogas Fuel: Case Study.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2010, vol. 42(6). 188 - 193
    [viewed 22 November 2019]. Available from: https://publications.waset.org/pdf/12876.