@inproceedings{semisupervisedlearningusingsparse,
  title = {Semi-supervised Learning using Sparse Eigenfunction Bases},
  author = {Kaushik Sinha and Mikhail Belkin},
  year = {2009},
  booktitle = {NeurIPS 2009 12},
  url = {http://papers.nips.cc/paper/3852-semi-supervised-learning-using-sparse-eigenfunction-bases},
}