1. There are many general references to CBD sales characteristics. As examples see: Edgar M. Horwood and Ronald R. Boyce,Studies of the Central Business District and Urban Freeway Development (Seattle: University of Washington Press, 1959) Raymond Vermon,The Changing Function of the Central City, Committee for Economic Development, January, 1959; and Shirley F. Weiss,The Central Business District in Transition (Department of City and Regional Planning, University of North Carolina, 1957).
2. For a discussion of the CBD census data limitations see: Horwood and Boyce,op. cit. p. 31.
3. Horwood and Boyce,op. cit., pp. 36–40.
4. Ibid. The mixture and changing composition of groups making up total CBD sales is currently being studied at the University of Illinois by Lorne H. Russwurm.
5. Ibid..