@article{JMLR:v8:xu07a,
  author  = {Yuesheng Xu and Haizhang Zhang},
  title   = {Refinable Kernels},
  journal = {Journal of Machine Learning Research},
  year    = {2007},
  volume  = {8},
  number  = {71},
  pages   = {2083--2120},
  url     = {http://jmlr.org/papers/v8/xu07a.html}
}