Iturrieta Rojas, A. and Neptune, A.M.L. 1971. Effect of macronutrients and iron upon the growth and mineral composition of castor bean (Ricinus Communis L.) cultivated in nutrient solution . Anais da Escola Superior de Agricultura Luiz de Queiroz. 28, (Jan. 1971), 31–67. DOI:https://doi.org/10.1590/S0071-12761971000100002.