1. and , Programming, Games and Transportation Networks, Wiley, New York (1965).
2. Minimal ratio spanning trees. Networks. (1977) 335–342.
3. and , Finding minimum spanning trees. SIAM J. Comput. (1976) 724–742.
4. Graph Theory: An Algorithmic Approach, Academic, New York (1975).
5. A good algorithm for smallest spanning trees with a degree constraint. Networks. (1978) 201–208.