@misc{
    NFAPackage,
    author = "Honkela, Antti and Valpola, Harri and Giannakopoulos, Xavier",
    url = "http://www.cis.hut.fi/projects/bayes/software/",
    flag = "SOFTWARE",
    year = "2000",
    title = "Nonlinear Factor Analysis {M}atlab package"
}