Grünbaum, Branko (2008). "Can every face of a polyhedron have many sides?". Geometry, games, graphs and education: the Joe Malkevitch Festschrift. Bedford, Massachusetts: Comap, Inc. pp. 9–26. hdl:1773/4593. MR2512345.
Grünbaum, Branko (2008). "Can every face of a polyhedron have many sides?". Geometry, games, graphs and education: the Joe Malkevitch Festschrift. Bedford, Massachusetts: Comap, Inc. pp. 9–26. hdl:1773/4593. MR2512345.