Ribeiro I. and  Tavares A.M. and  Sá E. and  Lopes M.,  Impacts of Biofuels on Air Quality: Northern Portugal Case Study.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2011, vol. 59(11). 742 - 747
    [viewed 19 March 2024]. Available from: https://publications.waset.org/pdf/5838.