Barnette, D. (1983). Map coloring, polyhedra, and the four-color problem. The Mathematical Association of America.
Chicago-čujuhus (17. p.)Barnette, David. Map Coloring, Polyhedra, and the Four-color Problem. Washington, D.C: The Mathematical Association of America, 1983.
MLA-čujuhus (9. p.)Barnette, David. Map Coloring, Polyhedra, and the Four-color Problem. The Mathematical Association of America, 1983.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.