1. Subtrees of directed graphs and hypergraphs, In Proceedings of the Eleventh Southeastern Conference on Combinatorics, Graph Theory and Computing (Florida Atlantic Univ., Boca Raton, Fla.), I, 28 (1980), pp. 227–239.
2. Paths with two blocks in k-chromatic digraphs
3. On directed paths and circuits, Theory of Graphs, and (Editors), Academic press, New York, 1968, pp. 115–118.
4. On Unavoidability of Trees with k Leaves
5. Median orders of tournaments: A tool for the second neighborhood problem and Sumner's conjecture