1. Adams F 1974 Soil solution. In The Plant Root and its Environment. Ed. E W Carson. pp 441?482. University Press of Virginia, Charlottesville, USA.
2. Anderson G 1975 Other organic phosphorus compounds. In Soil Components. Vol. 1. Organic Components. Ed. J E Gieseking. pp 305?331. Springer Verlag, Berlin, Germany.
3. Anderson G 1980 Assessing organic phosphorus in soils. In The Role of Phosphorus in Agriculture. Ed. F E Khasawneh. pp 411?431. ASA, CSSA, SSSA, Madison, WI, USA.
4. Boero G and Thien S 1978 Phosphatase actiity and phosphorus availability in the rhizosphere of corn roots. In The Soil-Root Interface. Eds. J L Harley and R S Russel. pp 231?243. Academic Press Inc., London, UK.
5. Boutin J P, Provot M and Roux L 1981 Effect of cycloheximide and renewal of phosphorus supply on surface acid phosphatase activity of phosphorus deficient tomato roots. Physiol. Plant. 51, 353?360.