Realization of Heawood's Map on a Toroidal Polyhedron
Heawood’s map consists of seven regions, with each pair sharing a part of its boundary. This Demonstration shows a realization of Heawood’s map on a toroid with congruent regions, each made of four triangles.
 L. Szilassi, "On Three Classes of Regular Toroids," Symmetry: Culture and Science, 11(1–4), 2000 pp. 317–335.
 B. M. Stewart, Adventures among the Toroids, 2nd ed., Okemos, MI: B. M. Stewart, 1980 pp. 199.