Colze, Leo. Berliner Warenhäuser, Vol. XLVII in “Grossstadt Dokumente” (Berlin, 1905).

Berlin stores. (III, 4; IV, 1; V, 1; IX, 1.)

Loeb, Moritz. Berliner Konfektionen, Vol. XV in “Grossstadt Dokumente” (Berlin, 1905).

Ready-made clothing establishments. (V, 1, 4; IX, 1.)

Parker, Horatio Newton. City Milk Supply (New York, 1917). (IV, 1.)

Shideler, E. H. “The Business Center as an Institution,” Jour. Appl. Sociol., IX (March, April, 1925), 269–75.

An outline of the local trade center in the urban community and its significance in city life. (IV, 1; V, 1, 2, 3; VII, 1, 2.)

9. One of the latest phases of city development is the direct result of the invention of a new technique of building. Steel construction has made possible the skyscraper, the elevated railroad, and the subway, and thus introduced a new dimension into city growth. This new technique has made possible a density, per unit of ground surface, which has given the city an entirely new complexion. The full effects of this new invention are still not fully known.

Holborn, I. B. S. “The City: The Outer Expression of an Inner Self,” Art World, III (December, 1917), 217–21. (III, 1; IX, 2.)

Mumford, Lewis. Sticks and Stones: A Study of American Civilization (New York, 1925).