Israel Journal of Mathematics
First and Last Page
A polyhedral map on the torus is diminimal if either shrinking or removing an edge yields a nonpolyhedral map. We show that all such maps on the torus fall into one of two classes, type 2 and type 3, and show that there are exactly two type 3 ones, which are given explicitly.
Riskin, A. Type 3 diminimal maps on the torus. Israel J. Math. 75, 371–379 (1991). https://doi.org/10.1007/BF02776033