Michael Formann Torben Hagerup James Haralambides Michael Kaufmann Frank Thomson Leighton Antonios Symvonis Emo Welzl Gerhard J. Woeginger 86-95 conf/focs/FOCS31a 1990 FOCS db/conf/focs/focs90.html#FormannHHKLSWW90 http://doi.ieeecomputersociety.org/10.1109/FSCS.1990.89527