@article{JMLR:v7:micchelli06a,
  author  = {Charles A. Micchelli and Yuesheng Xu and Haizhang Zhang},
  title   = {Universal Kernels},
  journal = {Journal of Machine Learning Research},
  year    = {2006},
  volume  = {7},
  number  = {95},
  pages   = {2651--2667},
  url     = {http://jmlr.org/papers/v7/micchelli06a.html}
}