Erdős, P.; Rubin, A. L.; Taylor, H. (1979). Choosability in graphsArchiválva2016. március 9-i dátummal a Wayback Machine-ben. In Proc. West Coast Conference on Combinatorics, Graph Theory and Computing, Arcata, Congr. Num. 26, 125–157.
Erdős, P.; Rubin, A. L.; Taylor, H. (1979). Choosability in graphsArchiválva2016. március 9-i dátummal a Wayback Machine-ben. In Proc. West Coast Conference on Combinatorics, Graph Theory and Computing, Arcata, Congr. Num. 26, 125–157.