| |
| 2000 | ||
|---|---|---|
| 2 | EE | Walter Wessel: A short solution of Heawood's empire problem on the torus and implications for higher genus. Discrete Mathematics 212(1-2): 161-165 (2000) |
| 1998 | ||
| 1 | EE | Walter Wessel: A short solution of Heawood's empire problem in the plane. Discrete Mathematics 191(1-3): 241-245 (1998) |