Dzhahirul Zamri, et al. “AC Breakdown Performance of Organic Transformer Oil Using Different Nano Oxide Fillers of ZnO, NiO and α-Fe2O3”. International Journal of Integrated Engineering, vol. 16, no. 7, Dec. 2024, pp. 313-26, https://penerbit.uthm.edu.my/ojs/index.php/ijie/article/view/19106.