References
- Committee of Soil Standard Methods for Analyses and Measurements . 1986 . Soil Standard Methods for Analyses and Measurements , Tokyo : Hakuyusha . (in Japanese)
- Egashira , K. and Tra , Ho Thi Lam . 1999 . Heavy metal status of agricultural soils in Tuliem and Thanhtri districts of Hanoi city, Vietnam . J. Fac. Agric., Kyushu Univ. , 43 : 489 – 497 .
- Kabata-Pendias , A. , Dudka , S. , Chlopecka , A. and Gawinowska , T. 1992 . “ Background levels and environmental influences on trace metals in soils of the temperate humid zone of Europe ” . In Biogeochemistry of Trace Metals , Edited by: Adriano , D.A. 61 – 84 . Boca Raton , Florida : Lewis Publishers .