Dantas, J.P. and Malavolta, E. 1983. Comparative response to N, P and K of grain sorghum and corn: I. Distrophic quartz sand . Anais da Escola Superior de Agricultura Luiz de Queiroz. 40, 2 (Jan. 1983), 865–889. DOI:https://doi.org/10.1590/S0071-12761983000200010.