@Inproceedings{ Zhao11-WITS,
  author = {K. Zhao and X. Zhao and J. Deng},
  title = {An Empirical Investigation of Online Gray Market},
  booktitle = {Proc. of the 21st Workshop on Information
Technologies and Systems (WITS 2011)},
  month = {December 3-4},
  year = {2011},
  pages = {},
  volume = {},
  address = {Shanghai, P. R. China} }