@Book{main:2007,
  editor    = {Candace Sidner  and  Tanja Schultz  and  Matthew Stone  and  ChengXiang Zhai},
  title     = {Human Language Technologies 2007: The Conference of the North American Chapter of the Association for Computational Linguistics; Proceedings of the Main Conference},
  month     = {April},
  year      = {2007},
  address   = {Rochester, New York},
  publisher = {Association for Computational Linguistics},
  url       = {http://www.aclweb.org/anthology/N/N07/N07-1}
}