@TECHREPORT\{IMM1984-03809,
    author       = "V. V. VIdal and H. Ravn and Z. Nahorski",
    title        = "Discrete maximum principle without directional convexity",
    year         = "1984",
    pages        = "20",
    number       = "",
    series       = "",
    institution  = "{IMSOR,} {DTH}",
    address      = "",
    type         = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3809-full.html"
}