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**Zentralblatt MATH**

**Publications of (and about) Paul Erdös**

**Zbl.No: ** 194.25102

**Autor: ** Erdös, Pál

**Title: ** Problems and results in chromatic graph theory (In English)

**Source: ** Proof Tech. Graph Theory, Proc. 2nd Ann Arbor Graph Theory Conf. 1968, 27-35 (1969).

**Review: ** [For the entire collection see Zbl 193.28103.]

Several problems and results in graph theory are discussed mostly connected with chromatic numbers. Here I only state some of those questions which have been solved in the mean time. Hajnal proved that an \aleph_{1} chromatic graph contains for every n > n_{0} a circuit of n edges. Poft constructed a four chromatic critical graph having more than n^{2}/16 edges and J. Spencer constructed a graph of n vertices which has more than n- log n/ log 2-c cliques of different sizes. Non of these results is published as yet.

**Classif.: ** * 05C15 Chromatic theory of graphs and maps

00A07 Problem books

**Index Words: ** topology

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