1- Acosta J.A., Martinez-Martinez S., Faz A., and Arocena J. 2011. Accumulations of major and trace elements in particle size fractions of soils on eight different parent materials. Geoderma, 161:30–42.
2- Alvarez J.M., Lopez-Valdivia L.M., Novillo J., Obrador A. and Rico M.I. 2006. Comparison of EDTA and sequential extraction tests for phytoavailability prediction of manganese and zinc in agricultural alkaline soils. Geoderma, 132: 450- 463.
3- Campbell C.R. and Plank C.O. 1998. Preparation of plant tissue for laboratory analysis. p. 37-50. In: Y.P Kalra (ed.) Handbook of Reference Methods for Plant Analysis. CRC Press, Taylor & Francis Group.
4- Ding Zh., Wang Q. and Hu X. 2011. Fractionation of Zn and Pb in bulk soil and size fractions of water-stable micro-aggregates of lead/zinc tailing soil under simulated acid rain. Procedia Environmental Sciences, 10: 325 – 330.
5- Ding Zh., Wang Q. and Hu X. 2013. Extraction of heavy metals from water-stable soil aggregates using EDTA. Procedia Environmental Sciences, 18: 679 – 685.
6- Fan J., Ding W., Chen Z. and Ziadi N. 2012. Thirty-year amendment of horse manure and chemical fertilizer on the availability of micronutrients at the aggregate scale in black soil. Environmental Science and Pollution Research, 19:2745 – 2754.
7- Fernandes J.C. and Henriques F.S. 1991. Biochemical, physiological and structural effects of excess copper in plants. The Bot. Rev. 57(3): 246-273.
8- Gee G.W. and Bauder J.W. 1986. Particle size analysis. In: Klute A. (ed.), Methods of Soil Analysis. Part 1. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
9- Hoyt P.B. and Nyborg M. 1971. Toxic metals in acid soil: 2. Estimation of plant available manganese. Soil Science Society of America Journal, 35:241-244.
10- Lexmond T.M. and Vorm P.D.f. 1981. The effect of pH on copper toxicity to hydroponically grown maize. Netherlands Journal of Agricultural Science. 29:217-238.
11- Lindsay W.L. and Norvell W.A. 1978. Development of a DTPA soil test for zinc, iron, manganese, and copper. Soil Science Society of America Journal, 42: 421-428.
12- Loeppert R.H. and Suarez D.L. 1996. Carbonate and gypsum. p. 437-474. In: D.L. Sparks. Methods of Soil Analysis. SSSA, Madison.
13- Luo C., Shen Z. and Li X. 2005. Enhanced phytoextraction of Cu, Pb, Zn and Cd with EDTA and EDDS. Chemosphere, 59: 1-11.
14- Marquez C.O., Garcia V.J., Cambardella C.A., Schultz R.C. and Isenhart T.M. 2004. Aggregate size-stability distribution and soil stability. Soil Science Society of America Journal, 68:725-726.
15- Mehlich A. 1953. Determination of P, Ca, Mg, K, Na and NH4. North Carolina Soil Testing Div. Mimeo, Raleigh.
16- Mehlich A. 1984. Mehlich 3 soil test extractant: A modification of Mehlich 2 extractant. Communications in Soil Science and Plant Analysis, 15: 1409-1416.
17- Nelson D.W. and Sommers L.E. 1982. Total carbon, organic carbon, and organic matter. p. 539–579. In A.L. Page et al. (ed.) Methods of Soil Analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
18- Nicholson F.A., Smith S.R., Alloway. B.J., Carlton-Smith C. and Chanbers B.J. 2003. An inventory of heavy metals inputs to agricultural soils in England and wales. Science of The Total Environment, 311:205-219.
19- Nriagu J.O., and Pacyna J.M. 1988. Quantitative assessment of worldwide contamination of air, water and soils by trace metals. Nature, 333:134-39.
20- Qian J., Shan X.Q., Wang Z.J. and Tu Q. 1996. Distribution and plant availability of heavy metals in different particle-size fractions of soil. Science of the Total Environment, 187:131- 141.
21- Quenea K., Lamy I., Winterton P., Bermond A. and Dumat C. 2009. Interactions between metals and soil organic matter in various particle size fractions of soil contaminated with waste water. Geoderma, 149:217 – 223.
22- Rengaraj S. and Moon S.H. 2002. Kinetics of adsorption of Co (II) removal from water and wastewater by ion exchange resins. Water research, 36:1783-93.
23- Rhoades J.D. 1996. Salinity: electrical conductivity and total dissolved solids. p. 417-435. In: D.L. Sparks (ed.), Methods of Soil Analysis. SSSA, Madison.
24- Skaggs T.H., Arya L.M., Shouse P.J. and Mohanty B.P. 2001. Estimating particle size distribution from limited soil texture data. Soil Science Society of American Journal, 65: 1038-1044.
25- Sposito G.L., Lund J. and Chang A.C. 1982. Trace metal chemistry in arid-zone field soils amended with sewage sludge: I. Fractionation of Ni, Cu, Zn, Cd, and Pb in solid phases.Soil Science Society of America Journal, 46:260-265.
26- Sumner M.E., and Miller P.M. 1996. Cation exchange capacity and exchange coefficient. In: D.L. Sparks (ed.), Methods of Soil Analysis. SSSA, Madison.
27- Takeda A., Tsukada H., Takaku Y., Hisamatsu S., Inaba J. and Nanzyo M. 2006. Extractability of major and trace elements from agricultural soils using chemical extraction methods: application for phytoavailability assessment. Soil Science and Plant Nutrition, 52 (4), 406–417.
28- Tembo B.D., Sichilongo K. and Cernak J. 2006. Distribution of copper, lead, cadmium and zinc concentrations in soils around Kabwe town in Zambia. Chemosphere, 63: 497–501.
29- Thomas G.W. 1996. Soil pH and soil acidity. p. 475-490. In: D.L. Sparks (ed.), Methods of Soil Analysis. SSSA, Madison.
30- Wang Q. Y., Liu J., Wang Y. and Yu H. 2015. Accumulations of copper in apple orchard soils: distribution and availability in soil aggregate fractions. Journal of Soils Sediments, 15:1075–1082.
31- Wilcke W. and Kaupenjohann M. 1997. Differences in concentrations and fractions of aluminium and heavy metals between aggregate interior and exterior. Soil Science, 162: 323.
32- Yoon J., Cao X., Zhou Q. and Lena Q.M. 2006. Accumulation of Pb, Cu, and Zn in native plants growing on a contaminated Florid a site. Science of the Total Environment, 368:456–464.
33- Zhang M.K., He Z.L., Calvert D.V., Stoffella P.J., Yang X.E. and Li Y.C. 2003. Phosphorus and heavy metal attachment and release in sandy soil aggregate fractions. Soil Science Society of America Journal, 67:1158–1167.