1. Griffiths, E.J. et al. (eds.): Environmental phosphorus handbook. New York: Wiley 1973
2. Phosphorus in the environment: Ciba Foundation Symposium 57 (new series). Amsterdam: Elsevier - Excerpta Medica - North Holland 1978
3. Emsley, J., Hall, C.D.: The chemistry of phosphorus. London: Harper and Row 1976
4. Williams, R.J.P.: Phosphorus biochemistry, p. 95 in [2]
5. Brinch, J.W.: World resources of phosphorus, p. 23 in [2]