ABSTRACT
When World War II ended, the continent was to a large extent devastated, libraries were severely affected by war damage, and the exchange of publications between institutions in the former German Reich and Western states, particularly the United States, had been broken off. Harris and Ullman wrote 'The Nature of Cities in, and about, Chicago, the center of urban ecology and of interdisciplinary cooperation between urban sociology and urban geography. New models for the American 'urbanlike' system have been developed. During the last 50 years, this new system of suburbia, which was growing rapidly, formed a kind of extensive network, destroying former central place hierarchies, developing the surroundings of metropolitan areas, and halting the process of restructuring of many central cities by means of downtown redevelopment and gentrification. Core cities of metropolises such as Chicago now have an opportunity for restructuring as nodes in air transport, as centers of finance, business, or the quaternary public sector, or as multicultural centers.
