Cita APA (7th ed.)
Wilson, R. J., & Stewart, I. Four Colors Suffice: How the Map Problem Was Solved (Nueva ed.). Princeton University.
Cita Chicago (17th ed.)
Wilson, Robin J., i Ian Stewart. Four Colors Suffice: How the Map Problem Was Solved. Nueva ed. Princeton, EUA: Princeton University.
Cita MLA (9th ed.)
Wilson, Robin J., i Ian Stewart. Four Colors Suffice: How the Map Problem Was Solved. Nueva ed. Princeton University.
Atenció: Aquestes cites poden no estar 100% correctes.