Petri Kouvo and  Aino Kainulainen and  Kimmo Koivunen,  Separate Collection System of Recyclables and Biowaste Treatment and Utilization in Metropolitan Area Finland.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2017, vol. 126(6). 515 - 519
    [viewed 19 November 2019]. Available from: https://publications.waset.org/pdf/10007264.