1. P. Erdős, Graph theory and probability,Canad. J. Math. 11 (1959), 34–38.
2. P. Erdős, F. Galvin andA. Hajnal, On set systems having large chromatic numbers and not containing prescribed subsystems,Coll. Math. Soc. János Bolyai 10,Infinite and Finite Sets, Keszthely (Hungary) 1973, 425–513.
3. P. Erdős andA. Hajnal, On chromatic number of graphs and set-systems,Acta Math. Acad. Sci. Hung. 17 (1966), 61–99.
4. P. Erdős, A. Hajnal andS. Shelah, On some general properties of chromatic numbers,Coll. Math. Soc. János Bolyai 8,Topics in Topology, Keszthely, (Hungary) 1973, 243–255.
5. P. Erdős andR. Rado, A construction of graphs without triangles having pre-assigned order and chromatic number,Journal of the London Math. Soc. 35 (1960), 445–448.