@inproceedings{spectralunsupervisedparsingwithadditive,
  title = {Spectral Unsupervised Parsing with Additive Tree Metrics},
  author = {Ankur P. Parikh and Shay B. Cohen and Eric P. Xing},
  year = {2014},
  booktitle = {ACL 2014 6},
  url = {https://aclanthology.org/P14-1100},
}