Meisters, G. H. "Polygons Have Ears." Amer. Math. Monthly82, 648-651, 1975.Meisters, G. H. "Principal
Vertices, Exposed Points, and Ears." Amer. Math. Monthly87, 284-285,
1980.Toussaint, G. "Anthropomorphic Polygons." Amer. Math.
Monthly98, 31-35, 1991.