@article{JMLR:v18:17-380,
  author  = {Hiroaki Sasaki and Takafumi Kanamori and Aapo Hyv{{\"a}}rinen and Gang Niu and Masashi Sugiyama},
  title   = {Mode-Seeking Clustering and Density Ridge Estimation via Direct Estimation of Density-Derivative-Ratios},
  journal = {Journal of Machine Learning Research},
  year    = {2018},
  volume  = {18},
  number  = {180},
  pages   = {1--47},
  url     = {http://jmlr.org/papers/v18/17-380.html}
}