1. An historical review of the gravity and potential concepts of human interaction;Carrothers;Journal of the American Institute of Planners,1956
2. A spatial model of urban stock and activity;Echenique;Regional Studies,1969
3. Spatial diffusion;Gould,1969
4. How accessibility shapes land use;Hansen;Journal of the American Institute of Planners,1959
5. The concept of accessibility: A search for an operational form;Ingram;Regional Studies,1970