K. K. Mann, A. W. Schumann, T. A. Obreza, W. G. Harris, and J. B. Sartain, “How to Characterize Soil Variability in Florida Citrus Groves as It Relates to Tree Growth and Yield: SL556/SS557, 1/2012”, EDIS, vol. 2012, no. 1, Jan. 2012.