1. Bondy, J.A., Murty, U.S.R.: Graph theory with applications. Amsterdam: North- Holland 1976
2. Borodin, O.V.: On the total coloring of planar graphs. J. Reine Ange. Math. 394, 180–185(1989)
3. Borodin, O.V.: Precise lower bound for the number of edges of minor weight in planar maps. Math. Slovaca 42, 129–142 (1992)
4. GrÜnbaum, B.: New views on some old questions of combinatorial geometry, in Theorie Combinatorie, Proc. Int. Colloquium, Rome, 1973, Accademia nay. dei. lincei Rome 1, 451–468 (1976)
5. GrÜnbaum, B.: Polytopal graphs, in Studies in Graph Theory (D.R. Fulkerson, ed.), MAA Studies in Mathematics 12, 201–224 (1975)