Four colour theorem

Eitemau Tebyg

• Four-color problem
  gan: Ore, Oystein
  Cyhoeddwyd: (1967)
• Guide to graph colouring: Algorithms and applications
  gan: Lewis, R M R.
  Cyhoeddwyd: (2016)
• Four colour theorems: history topological foundations and idea of proof/
  gan: Fritsch, Rudolf
  Cyhoeddwyd: (1998)
• The four color theorem : history, topological foundations, and idea of proof /
  gan: Fritsch, Rudolf
  Cyhoeddwyd: (1998)
• The four color theorem : history, topological foundations, and idea of proof /
  gan: Fritsch, Rudolf, et al.
  Cyhoeddwyd: (1998)