1. Jiyi Wu: Telecommunications Science, Vol. 12 (2009) No 22, pp.51-53.
2. Xinhe Li: Finance and Accounting, Vol. 2 (2008) No 13, pp.37-39.
3. Wei Liu: Computer Research and Development, Vol. 10 (2012) No 13, pp.10-12.
4. Junzhou Luo: Journal on Communications, Vol. 7 (2011) No10, pp.128-130.
5. Ying He: Financial Communications, Vol. 2 (2010) No 12, pp.13-14.