رازی میان رنگ‌ها: حدس بهزاد

       Behzad, M. (1965). Graphs and Their Chromatic Numbers (Ph.D. thesis, Michigan State University

 Chetwynd, A. G., & Hilton, A. J. W. (1989). A Δ-subgraph condition for a graph to be class 1. Journal of Combinatorial Theory

 Jensen, T. R., & Toft, B. (1995). Graph Coloring Problems. John Wiley & Sons

 Vizing, V. G. (1964). On an estimate of the chromatic class of a p-graph. Diskret