@article{10_37236_1032,
     author = {Winston C. Yang},
     title = {Adding layers to bumped-body polyforms with minimum perimeter preserves minimum perim\-eter},
     journal = {The electronic journal of combinatorics},
     year = {2006},
     volume = {13},
     doi = {10.37236/1032},
     zbl = {1080.05017},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1032/}
}