1. Aderikin, P. G., The role of exchangeable cations on the absorption of phosphoric acid by chernozems. Pochvovedenie1949, 302?306 (1949).
2. Allison, L. E., The trend of phosphate adsorption by inorganic colloids from certain Indiana Soils. Soil Sci.55, 333?342 (1943)
3. Arambarri, P. and Talibudeen, O., Factors influencing the isotopically exchangeable phosphate in soils. Part I. The effect of very small concentrations of organic anions. Plant and Soil11, 343?354 (1959).
4. Barbier, G., Chabannes, J., and Miallet, P., Absorption des ions phosphoriques à la surface des colloides argileux par l'intermediaire des alealino-terreux. Ann. Agron.16, 7?20 (1946).
5. Bjerrum, N., Calcium orthophosphate. Part I. Kgl. Danske Videnskab. Selskab Mat-fys. Medd.31(7, 1?68 (1958).