Waluyo, W., N. I. Sinisuka, S. Suwarno, and M. A. Djauhari. “Leakage Current and Pollutant Properties of Porcelain Insulators from the Geothermal Area”. ECTI Transactions on Electrical Engineering, Electronics, and Communications, vol. 8, no. 1, July 2009, pp. 126-45, doi:10.37936/ecti-eec.201081.172053.