On the maximum diameter of $k$-colorable graphs

Éva Czabarka, Inne Singgih, László A. Székely

Erdős, Pach, Pollack and Tuza [J. Combin. Theory, B 47, (1989), 279-285] conjectured that the diameter of a $K_{2r}$-free connected graph of order $n$ and minimum degree $\delta \ge 2$…