@article{JMLR:v7:passerini06a,
  author  = {Andrea Passerini and Paolo Frasconi and Luc De Raedt},
  title   = {Kernels on Prolog Proof Trees: Statistical Learning in the ILP Setting},
  journal = {Journal of Machine Learning Research},
  year    = {2006},
  volume  = {7},
  number  = {11},
  pages   = {307--342},
  url     = {http://jmlr.org/papers/v7/passerini06a.html}
}