Harger, Nelson, Osmar R. Brito, Ricardo Ralisch, Fábio Rogério Ortiz, and Toshio Sérgio Watanabe. 2007. “Evaluation of Sources and Rates of P Fertilizers on the Initial Growth of Corn”. Semina: Ciências Agrárias 28 (1):39-44. https://doi.org/10.5433/1679-0359.2007v28n1p39.