1. Solution of Kotzig's and Grünbaum's problems on the separability of a cycle in planar graph (in Russian);Borodin;Matem. Zametki,1989
2. Minimal weight of a face in planar triangulations without 4-vertices (in Russian);Borodin;Matem. Zametki,1992
3. From the theory of eulerian polyhedrons (in Russian);Kotzig;Mat. Čas.,1963
4. Extremal polyhedral graphs;Kotzig;Ann. New York Acad. Sci.,1979