Ilker Kalkan and  Saruhan Kartal,  Torsional Rigidities of Reinforced Concrete Beams Subjected to Elastic Lateral Torsional Buckling.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2017, vol. 127(7). 969 - 972
    [viewed 19 November 2019]. Available from: https://publications.waset.org/pdf/10007630.