S.F.S. Draman and  R. Daik and  A. Musa,  Synthesis and Fluorescence Spectroscopy of Sulphonic Acid-Doped Polyaniline When Exposed to Oxygen Gas.   journal   = {International Journal of Chemical and Molecular Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2009, vol. 27(3). 183 - 190
    [viewed 21 January 2020]. Available from: https://publications.waset.org/pdf/6634.