Hutasuhut, D. I. G., Ommi Alfina, Nita Syahputri, S. F. Sihotang, Efani Desi, and Siti Aliyah. “Expert System Detects Boiler Engine Damage Using Certainty Factors”. U-NET Jurnal Teknik Informatika, Vol. 5, no. 2, Aug. 2021, pp. 67-75, doi:10.52332/u-net.v5i2.350.