7Alloway B J.Heavy metals in soils[M].London:Blackie Academic & Professional,1995:1-65.
8Pllrves D.Trace element contamination of the environment[M].New York:Elsevier,1985:23-45.
9Cezary K,singh B R.Fractionation and mobility of copper,lead and zinc in soil profiles in the vicinity of a copper smelter[J].J Environ Qual,2001,30:485-492.
10Iyengar S S,Martens D C,Miller W P.Distribution and plant availability of soil zinc fractions[J].Soil Sci Soc Am J,1981,45:735-739.