1. Beuselinck, L., Govers, G., Poesen, J., Degraer, G. and Froyen, L. (1998) Grain-size analysis by laser diffractometry: Comparison with the sieve-pipette method. Catena 32, 193-208.
2. Selenium geochemistry of paddy soils in Yangtze River Delta
3. Chen, D. Z., Li, J. Y. and Ren, S. X. (1985) Selenium in the ecosystems of Shaanxi Province, China. Acta Geographica Sinica 40, 307-321 (in Chinese with English abstract).
4. Chen, J. and Wang, H. N. (2004) Geochemistry. Science Press, Beijing, 37 pp. (in Chinese).
5. Cheng, B. R., Ju, J. S., Qiu, S. R., He, R. Z. and Sheng, S. J. (1980) Selenium in soils of Northeastern China. Acta Pedoligica Sinica 17, 55-61 (in Chinese with English abstract).