1. Beck, J.: On three-chromatic hypergraphs. Discrete Math.29, 127–137 (1978)
2. Erdös, P.: On a combinatorial problem II. Acta Math. Acad. Sci. Hung.15, 445–447 (1964)
3. Erdös, P.: Some old and new problems in various branches of combinatorics. In: Proceedings of the Tenth Southeastern Conference on Combinatorics, Graph Theory and Computing. Congressus Numerantium XXIII, pp. 19–37. Winnipeg: Utilitas Mathematica 1979
4. Erdös, P., Hajnal, A.: On a property of families of sets. Acta Math. Acad. Sci. Hung.12, 87–123 (1961)
5. Erdös, P., Lovász, L.: Problems and results on 3-chromatic hypergraphs and some related questions. In: Infinite and Finite Sets. Colloq. Math. Soc. János Bolyai10, 609–627 (1975)