Hannu Nurmesniemi and  Mikko Mäkelä and  Risto Pöykiö and  Olli Dahl,  Comparison of The Fertilizer Properties of Ash Fractions from Medium-Sized (32 MW) and Small-Sized (6 MW) Municipal District Heating Plants.   journal   = {International Journal of Chemical and Molecular Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2011, vol. 51(3). 252 - 256
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/11180.