WASET
    Sunan Payungsak and  Atchana Wongchaisuwat and  Ladda Meesuk,   [Ca(2,2'-bipyridine)3]2+ -Montmorillonite: A Potentiometric Sensor for Sulfide ion.   journal   = {International Journal of Chemical and Molecular Engineering}, [online]. World Academy of Science, Engineering and Technology.
    July 2012, vol. 67(7). 608 - 611
    [viewed 28 March 2024]. Available from: https://publications.waset.org/pdf/3449.