1. See references in: W.L. Garrison, “Spatial Structure of the Economy, II,”Annals, Association of American Geographers, vol. 49 no. 4, December 1959, pp. 471–82.
2. R. E. Quandt, “Models of Transportation and Optimal Network Construction,”Journal of Regional Science, vol. 2 no. 1, Spring 1960, pp. 27–46.
3. See, for example: Chicago Area Transportation Study,Final Report (vol. 3), Chicago, [the Study], 1962.
4. William L. Garrison and Duane F. Marble,The Structure of Transportation Networks, Washington, U.S. Department of Commerce, Office of Technical Services, 1961 (Report to the U.S. Army Transportation Research Command under contract DA-44-177-TC-685).
5. See, for example: Claude Berge,The Theory of Graphs and its Applications (translated by Alison Doig), New York, John Wiley, 1962.