Abu, M.L. et al. 2020. Evaluation of Soil Amended with Graded Levels of Craseonycteris thonglongyai Dung on the Improvement of Mineral Element Constituents in the Leaf of Cnidoscolus aconitifolius (Tree Spinach): doi.org/10.26538/tjnpr/v4i11.29. Tropical Journal of Natural Product Research (TJNPR). 4, 11 (Nov. 2020), 1015–1018.