@article {sdbackerNaudpscheund1998,
	title = {Non-linear Dimensionality Reduction Techniques for Unsupervised Feature Extraction},
	journal = {Pattern Recognition Letters},
	volume = {19},
	year = {1998},
	pages = {711-720},
	author = {Steve De Backer and A. Naud and Paul Scheunders}
}
