Maciel-Torres, S. P. et al. 2017. Micronutrients in castor-oil plants (Ricinus communis L.) growing in soil fertilized with biosolids. Revista Chapingo Serie Zonas Áridas. 16, 2 (Dec. 2017), 13–22. DOI:https://doi.org/10.5154/r.rchza.2017.10.007.