M. Z. Alsawalha,  Basicity of Jordanian Natural Clays Studied by Pyrrole-tpd and Catalytic Conversion of Methylbutynol.   journal   = {International Journal of Chemical and Materials Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2018, vol. 133(1). 33 - 37
    [viewed 12 August 2020]. Available from: https://publications.waset.org/pdf/10008730.