Diana, N. ., E. Ginting, and P. K. Karo. “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%”. Journal of Energy, Material, and Instrumentation Technology, vol. 3, no. 4, Nov. 2022, pp. 138-46, doi:10.23960/jemit.v3i4.114.