O.P, A., A. P., and A. A. A. “Phytoaccumulation of Zinc and Iron by Jatropha Curcas Grown in Used Lubrication Oil-Contaminated Soil”. Malaysian Journal of Science, vol. 29, no. 3, Dec. 2010, pp. 207-13, doi:10.22452/mjs.vol29no3.3.