1. W. Lindsay, Chemical Equilibria in Soils, Wiley, New York, 1979, pp. 163–209.
2. W.E. Brown, Environmental Phosphorus Handbook, Wiley, New York, 1973, pp. 203–239.
3. Phosphates in detergents and the entrophication of America's waters, 23rd Rep. Commission on Govt. Operation, US Printing Office, Washington DC, 1970, p. 27
4. Lake Water and Sediment
5. J. Basset, R.C. Denney, G.H. Jeffery, J. Mendham, Vogel's Textbook of Quantitative Inorganic Analysis, Longman, New York, 1973, pp. 741–742.