Vertex coverings by monochromatic cycles and trees

P Erdős, A Gyárfás, L Pyber
1991 Journal of combinatorial theory. Series B (Print)  
If the edges of a finite complete graph K are colored with r colors then the vertex set of K can be covered by at most cr2 log r vertex disjoint monochromatic cycles. Several related problems are discussed.
doi:10.1016/0095-8956(91)90007-7 fatcat:dkyocj5f3jfvtdkqngr6e72nay