# Reference Request: Graph Edge Density

I was curious if there was a reference which answers the question, What is the maximum number of edges in a graph $G$ with $n$ vertices which does not contain a $5$-cycle? $k$-cycle? The analogous question for $k=4$ is well known.

For cycles of odd length, the only extremal graphs for large $n$ are complete bipartite graphs with the sides as equal as possible. For smaller $n$ there can be other extremal graphs. The complete story was worked out fairly recently by Füredi and Gunderson.