The Structure of Bull-Free Perfect Graphs
Maria Chudnovsky, Irena Penev · Journal of Graph Theory · 2012
The bull is a graph consisting of a triangle and two vertex-disjoint pendant edges. A graph is called bull-free if no induced subgraph of it is a bull. A graph G is perfect if for every induced subgraph H of G, the chromatic number of H equals the size of the largest complete subgraph of H. This article describes the structure of all bull-free perfect graphs.