@conference{
    AFPNMFA,
    author = "Yuan, Zhijian and Oja, Erkki",
    timestamp = "2008.12.01",
    booktitle = "Proceedings of the 9th International Symposium on Signal Processing and its Applications",
    year = "2007",
    flaggs = "RAE",
    title = "A family of projective nonnegative matrix factorization algorithms"
}