1. Diagrams and Schlegel-diagrams;Barnette,1970
2. An invertible non-polyhedral diagram;Barnette;Israel J. Math.,1980
3. A 3-sphere that is not 4-polyhedral;Barnette;Studia Sci. Math. Hung.,1971
4. Convex Polytopes;Grünbaum,1967
5. Nicht-dualisierbare Sphären;Kleinschmidt;Geom. Dedicata,1977