Danikas, M., and S. Morsalin. “Foreign Inclusions, Enclosed Cavities, Partial Discharge Models and Discharge Energy: A Short Review Regarding Solid Dielectrics and Composite Insulating Systems”. Engineering, Technology & Applied Science Research, vol. 9, no. 5, Oct. 2019, pp. 4659-66, doi:10.48084/etasr.2958.