@inproceedings{viswanath-2009-activity,
  author = {Bimal Viswanath and Alan Mislove and Meeyoung Cha and Krishna P. Gummadi},
  title = {{On the Evolution of User Interaction in Facebook}}, 
  booktitle = {{Proceedings of the 2nd ACM SIGCOMM Workshop on Social Networks (WOSN'09)}},
  address = {{Barcelona, Spain}},
  month = {{August}},
  year = {{2009}}
}