Severino, Liv Soares, et al. “Growth and Yield of Castor Bean Fertilized With Macronutrients and Micronutrients”. Pesquisa Agropecuaria Brasileira, vol. 41, no. 4, Apr. 2006, pp. 563-8, doi:10.1590/S1678-3921.pab2006.v41.7175.