Thabit, Jassim M., and Hawkar B. Bakir. “In Situ Measuring of Relative Dielectric Permittivity to Calculate Electromagnetic Wave Velocity”. Iraqi Journal of Science, vol. 57, no. 3C, Feb. 2022, pp. 2252-7, https://www.ijs.uobaghdad.edu.iq/index.php/eijs/article/view/6456.