@ARTICLE\{IMM2006-04122,
    author       = "M. E. Kilmer and P. C. Hansen and M. I. Espaņol",
    title        = "A projection-based approach to general-form Tikhonov regularization",
    year         = "2006",
    journal      = "{SIAM} J. Sci. Comput.",
    volume       = "",
    editor       = "",
    number       = "",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/4122-full.html"
}