1. Geophagy and the involuntary ingestion of soil;Abrahams,2005
2. Agency for Toxic Substances and Disease registry (ATSDR), 2000. Summary Report for the ATSDR Soil-Pica Workshop, June 2000, Atlanta, Georgia, USA.
3. On the distribution of heavy metals as compared to some other elements between grain size fractions in soils;Andersson;Swed. J. Agric. Res.,1979
4. Baars, A.J., Theelen, R.M.C., Janssen, P.J.C.M., Hesse, J.M., van Apeldoorn, M.E., Meijerink, M.C.M., Verdam, L., Zeilmaker, M.J., 2001. Re-evaluation of human-toxicological maximum permissible risk levels. RIVM Report 711701025.
5. Effect of particle size on lead adsorption from the gut;Barltrop;Arch. Environ. Health.,1979