Style de citation APA (7e éd.)

Appel, K. I., & Haken, W. (1989). Every planar map is four colorable. American Mathematical Society.

Style de citation Chicago (17e éd.)

Appel, Kenneth I., et Wolfgang Haken. Every Planar Map Is Four Colorable. Providence: American Mathematical Society, 1989.

Style de citation MLA (9e éd.)

Appel, Kenneth I., et Wolfgang Haken. Every Planar Map Is Four Colorable. American Mathematical Society, 1989.