@INPROCEEDINGS{ZwaBla06a,
    author = "Zwald, Laurent and Blanchard, Gilles",
    title = "On the convergence of eigenspaces in kernel principal components analysis",
    booktitle = "Advances in Neural Inf. Proc. Systems (NIPS 05)",
    year = "2006",
    volume = "18",
    pdf = "http://books.nips.cc/papers/files/nips18/NIPS2005\_0468.pdf"
}