Herbert Edelsbrunner Leonidas J. Guibas John Hershberger Raimund Seidel Micha Sharir Jack Snoeyink Emo Welzl Implicitly Representing Arrangements of Lines or Segments. 56-69 1988 Symposium on Computational Geometry http://doi.acm.org/10.1145/73393.73400 db/conf/compgeom/compgeom88.html#EdelsbrunnerGHSSSW89