“EFFECT OF ADDING CARBON POWDER, ANTRACITE, AND WOOD CHARCOAL AGAINST THE HARDNESS OF AMUTITE STEEL IN THE PROCESS OF HEAT TREATMENT WITH MEDIA COOLING WATER, SEA WATER, ICE WATER AND OIL” (2021) PROCEEDINGS OF NATIONAL COLLOQUIUM RESEARCH AND COMMUNITY SERVICE, 5, pp. 5–8. doi:10.33019/snppm.v5i0.2672.