Turner, B.L., Kay, M.A., Westermann, D.T. 2004. Phosphorus in surface runoff from calcareous arable soils of the semiarid western united states. Journal of Environmental Quality. 33(5):1589-1946.
Turner, B.L., Kay, M.A., Westermann, D.T. 2004. Colloidal phosphorus in surface runoff and water extracts from semi-arid soils of the western united states. Journal of Environmental Quality. 33:1464-1472.