Wilson R. Robin. (2003). Four Colours Suffice. How the Map Problem was Solved. London, Penguin Books, 2003.
Chicago Style (17th ed.) CitationWilson R. Robin. Four Colours Suffice. How the Map Problem Was Solved. London, Penguin Books, 2003, 2003.
MLA (9th ed.) CitationWilson R. Robin. Four Colours Suffice. How the Map Problem Was Solved. London, Penguin Books, 2003, 2003.
Warning: These citations may not always be 100% accurate.