Bingchun Liu and  Pei-Chann Chang and  Natasha Huang and  Dun Li,  Multi-Level Air Quality Classification in China Using Information Gain and Support Vector Machine.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2018, vol. 144(12). 1092 - 1101
    [viewed 31 May 2020]. Available from: https://publications.waset.org/pdf/10009891.