@article{JMLR:v14:chalupka13a,
  author  = {Krzysztof Chalupka and Christopher K. I. Williams and Iain Murray},
  title   = {A Framework for Evaluating Approximation Methods for Gaussian Process Regression},
  journal = {Journal of Machine Learning Research},
  year    = {2013},
  volume  = {14},
  number  = {10},
  pages   = {303--331},
  url     = {http://jmlr.org/papers/v14/chalupka13a.html}
}