@INPROCEEDINGS{ICASSP09-user-tagged, 
  author = {Xirong Li and Cees G. M. Snoek and Marcel Worring}, 
  title = {Annotating Images by Harnessing Worldwide User-Tagged Photos}, 
  booktitle = {Proceedings of the {IEEE} International Conference on Acoustics, Speech, and Signal Processing}, 
  pages = {3717-3720}, 
  month = {April}, 
  year = {2009},
  address = {Taipei, Taiwan}, 
}