Sumpena, Sumpena, Hb. Sukarjo, Wardoyo Wardoyo, and Soksono Singgih Pramana. 2021. “Analisa Kekerasan Dan Keausan Cylinder Sleeve Dari Besi Cor Kelabu FC250 Hasil Sand Mold Casting”. Jurnal Engine: Energi, Manufaktur, Dan Material 5 (2):97-103. https://doi.org/10.30588/jeemm.v5i2.944.