@article{unetmachinereadingcomprehensionwith,
  title = {U-Net: Machine Reading Comprehension with Unanswerable Questions},
  author = {Fu Sun and Linyang Li and Xipeng Qiu and Yang Liu},
  year = {2018},
  eprint = {1810.06638},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1810.06638v1},
}