@article{JMLR:v14:clark13a,
  author  = {Alexander Clark},
  title   = {Learning Trees from Strings: A Strong Learning Algorithm for some Context-Free Grammars},
  journal = {Journal of Machine Learning Research},
  year    = {2013},
  volume  = {14},
  number  = {111},
  pages   = {3537--3559},
  url     = {http://jmlr.org/papers/v14/clark13a.html}
}