@TECHREPORT\{IMM2002-01045,
    author       = "M. L. Andersen",
    title        = "Subspace preconditioned {LSQR} in {3-D} geomagnetic reconstruction",
    year         = "2002",
    number       = "",
    series       = "IMM-TR-2002-15",
    institution  = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/1045-full.html"
}