1. Landpissebedden. KNNV wetenschappelijke mededeling 221;Berg,1997
2. A survey of Pb, Cu, Zn, Cd, Cr, As and Se in earthworms and soil from diverse sites;Beyer;Environmental Monitoring and Assessment,1987
3. Relation of pH and other soil variables to concentrations of Pb, Cu, Zn, Cd and Se in earthworms;Beyer;Pedobiologia,1987
4. Millipedes;Blower,1985
5. Biodiversity and ecosystem functioning in soil;Brussaard;Ambio,1997