@ARTICLE{SchSmoMue98,
    author = {Sch\"olkopf, B. and Smola, A.J. and M\"uller, K.-R.},
    title = "Nonlinear component analysis as a kernel eigenvalue problem",
    journal = "Neural computation",
    year = "1998",
    volume = "10",
    pages = "1299--1319",
    number = "5"
}