@InProceedings{suzuki-EtAl:2003:ACL,
  author    = {Jun Suzuki  and  Tsutomu Hirao  and  Yutaka Sasaki  and  Eisaku Maeda},
  title     = {Hierarchical Directed Acyclic Graph Kernel: Methods for Structured Natural Language Data},
  booktitle = {Proceedings of the 41st Annual Meeting of the Association for Computational Linguistics},
  month     = {July},
  year      = {2003},
  address   = {Sapporo, Japan},
  publisher = {Association for Computational Linguistics},
  pages     = {32--39},
  url       = {http://www.aclweb.org/anthology/P03-1005},
  doi       = {10.3115/1075096.1075101}
}