Grant, R., Kronvang, B., Laubel, A., Tunney, H. (red.), Carton, O. T. (red.), Brookes, P. C. (red.) & Johnston, A. E. (red.) (1997).
Catchment Studies of the Loss of Phosphorus from Agriculture to Surface Water. I H. Tunney, O. T. Carton, P. C. Brookes & A. E. Johnston (red.),
Phoshorus Loss from Soil to Water (s. 383-384). Wallingford, UK: CAB International.