Wahl, J., M. Maboeta, H. Eijsackers, and L. van Rensburg. “Soil Ecological Risk Assessments of Selected South African Soils and Derivation of Soil Quality Standards”. Suid-Afrikaans Tydskrif Vir Natuurwetenskap En Tegnologie / <i>South African Journal of Science and Technology</I&gt;, Vol. 32, no. 1, Dec. 2013, p. 2 pages, doi:10.4102/satnt.v32i1.830.