Wenguang Ding and  Yang Wu and  Xia Wang and  Yayu Gao,  Family-size Biogas Plant Using Manure and Urine Mixture at Ambient Temperature in Semi-arid Regions of Northwestern China.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2010, vol. 41(5). 131 - 139
    [viewed 18 April 2024]. Available from: https://publications.waset.org/pdf/8186.