@article{JMLR:v9:caponnetto08a,
  author  = {Andrea Caponnetto and Charles A. Micchelli and Massimiliano Pontil and Yiming Ying},
  title   = {Universal Multi-Task Kernels},
  journal = {Journal of Machine Learning Research},
  year    = {2008},
  volume  = {9},
  number  = {52},
  pages   = {1615--1646},
  url     = {http://jmlr.org/papers/v9/caponnetto08a.html}
}