@ARTICLE\{IMM1987-03688,
    author       = "V. V. Vidal",
    title        = "On the sufficiency of the linear maximum principle",
    year         = "1987",
    keywords     = "optimization, control, maximum principle",
    pages        = "256-265",
    journal      = "Journal of Optimization Theory and applications",
    volume       = "54",
    editor       = "",
    number       = "",
    publisher    = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3688-full.html"
}