TY - JOUR AU - Winston C. Yang TI - Adding layers to bumped-body polyforms with minimum perimeter preserves minimum perim\-eter JO - The electronic journal of combinatorics PY - 2006 VL - 13 UR - http://geodesic.mathdoc.fr/articles/10.37236/1032/ DO - 10.37236/1032 ID - 10_37236_1032 ER -