@Article{Surdeanu:2011,
  author    = {Mihai Surdeanu and Massimiliano Ciaramita and Hugo Zaragoza},
  title     = {Learning to Rank Answers to Non-Factoid Questions from Web Collections},
  journal = {Computational Linguistics},
  volume = {37},
  number = {2},
  year      = {2011},
}