@article{directdensityderivativeestimationandits,
  title = {Direct Density-Derivative Estimation and Its Application in KL-Divergence Approximation},
  author = {Hiroaki Sasaki and Yung-Kyun Noh and Masashi Sugiyama},
  year = {2014},
  eprint = {1406.7638},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1406.7638v1},
}