Diana, N. .; Ginting, E.; Karo, P. K. The Effect of Cacao Leaf Extract As An Inhibitor With A Concentration Variation of 0%, 3%, 5%, And 7% on The Corrosion Rate of St 37 Steel With Immersion Time of 3 Days And 6 Days in NaCl Corrosive Medium 3%. J. Energy Mater. Instrum. Technol. 2022, 3, 138-146.