1. Liangzhu, Wang. Metal World, vol 5, (2000), p.12. (In Chinese).
2. Bolan Nanthi, S. Makino Tomoyuki, Kunhikrishnan. Anitha submitted to Donald, L. Sparks. Advances in Agronomy(2013).
3. Xuexiu, Chang, Chuanhao, Wen, Huanxiao, Wang. Yunan Environmental Science, vol 19 (2000), pp.59-61. (In Chinese).
4. Xiangying, Hao, Hui Zhao, Wei Liu. Inner Mongolia Environmental Protection, Vol 3, (2004), pp.27-28. (In Chinese ).
5. J. I. S. Khattar, Shailza. Proeess Biochemistry, Vol 44(2009), pp.118-121.