@article{JMLR:v6:ong05a,
  author  = {Cheng Soon Ong and Alexander J. Smola and Robert C. Williamson},
  title   = {Learning the Kernel with Hyperkernels},
  journal = {Journal of Machine Learning Research},
  year    = {2005},
  volume  = {6},
  number  = {36},
  pages   = {1043--1071},
  url     = {http://jmlr.org/papers/v6/ong05a.html}
}