1. Trace elements in the terrestrial environments;Adriano,2001
2. Heavy metals in soils;Alloway,1995
3. Standard Methods for the examination of water and wastewater;APHA,1993
4. Total content of nine mineral elements in 50 selected benchmark soil profiles of California;Bradford;Hilgardia,1967
5. Background concentrations of trace and major elements in California soils;Bradford,1996