WASET
    Snezhana P. Kostova and  Krassi V. Rumchev and  Todor Vlaev and  Silviya B. Popova,  Using Copulas to Measure Association between Air Pollution and Respiratory Diseases.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2012, vol. 71(11). 703 - 708
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/15542.