@ARTICLE{Saegusa2004,
  author = {Saegusa, Ryo and Sakano, Hitoshi and Hashimoto, Shuji},
  title = {Nonlinear Principal Component Analysis to Preserve the Order of Principal Components},
  journal = {Neurocomputing},
  year = {2004},
  volume = {61},
  pages = {57--70}
}