1. and Not every 2-tough graph is Hamiltonian, preprint, Memorandum No. 1400, Universiteit Twente, July 1997.
2. ?Hamiltonian graphs,? and eds., Selected topics in graph theory, Academic, London and New York, 1978, pp. 127-167.
3. and Tough enough chordal graphs are Hamiltonian, preprint.
4. Tough graphs and hamiltonian circuits
5. An upper bound on the shortness exponent of 1-tough, maximal planar graphs