1. Christaller central place structures: An introductory statement;Alao,1977
2. Mobility of resources, accessibility of knowledge, and economic growth;Andersson;Behavioral Science,1981
3. Economic dynamics;Baumol,1970
4. A continuous model of transportation;Beckmann;Econometrica,1952
5. The analysis of spatial diffusion processes;Beckmann;Papers of the Regional Science Association,1970