@InProceedings{hirao-EtAl:2013:EMNLP,
  author    = {Hirao, Tsutomu  and  Yoshida, Yasuhisa  and  Nishino, Masaaki  and  Yasuda, Norihito  and  Nagata, Masaaki},
  title     = {Single-Document Summarization as a Tree Knapsack Problem},
  booktitle = {Proceedings of the 2013 Conference on Empirical Methods in Natural Language Processing},
  month     = {October},
  year      = {2013},
  address   = {Seattle, Washington, USA},
  publisher = {Association for Computational Linguistics},
  pages     = {1515--1520},
  url       = {http://www.aclweb.org/anthology/D13-1158}
}