@INPROCEEDINGS{fujishima99,
  author = {Yuzo Fujishima and Kevin Leyton-Brown and Yoav Shoham},
  year = 1999,
  pages = "548--553",
  title = {Taming the Computational Complexity of Combinatorial Auctions:
          Optimal and Approximate Approaches},
  booktitle = {International Joint Conferences on Artificial Intelligence (IJCAI)}
}