@TechReport{knoll:07:implicits,
    title       = { {F}ast and {R}obust {R}ay {T}racing of {G}eneral {I}mplicits on the {GPU} },
    author      = { Aaron Knoll and Younis Hijazi and Andrew Kensler and Mathias Schott and Charles Hansen and Hans Hagen },
    year        = { 2007 },
    institution = { SCI Institute, University of Utah },
    number      = { UUSCI-2007-014 }
    note        = { (Conditionally accepted for publication in Computer Graphics Forum) }
}