Abbas Ali Mahmood Karwi,  Use of Detectors Technology for Gamma Ray Issued from Radioactive Isotopes and its Impact on Knowledge of Behavior of the Stationary Case of Solid Phase Holdup.   journal   = {International Journal of Physical and Mathematical Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2012, vol. 63(3). 289 - 292
    [viewed 22 September 2019]. Available from: https://publications.waset.org/pdf/6043.