Lasheen, Taysser, et al. “Reductive Leaching Kinetics of Low Grade Manganese Deposits in H2SO4 Solution Using Malonic Acid As Reducing Agent”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 15, no. 1, Apr. 2014, pp. 151-63, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/2062.