Kochen-Specker Theorem: Two Geometric Proofs
  We present two geometric proofs of the Kochen-Specker theorem. A quite similar argument has been used by Cooke, Keane, and Moran, as well as by Kalmbach in her book to derive the Gleason theorem. 
Cristian S. Calude, Peter H. Hertling, Karl Svozil
quant-ph