@ARTICLE{NolZieNik08,
    author = {Nolte, G. and Ziehe, A. and Nikulin, V. and Schl\"ogl, A. and Kr\"amer, N. and Brismar, T. and M\"uller, K.-R.},
    title = "{Robustly Estimating the Flow Direction of Information in Complex Physical Systems}",
    journal = "Physical Review Letters",
    month = "June",
    volume = "100",
    year = "2008",
    url = "http://doc.ml.tu-berlin.de/causality",
    pdf = "http://doc.ml.tu-berlin.de/causality/psi.pdf",
    pages = "234101"
}