Katcher, Leopold (pseudonym, “Spektator”). _Berliner Klubs_, Vol. XXV in “Grossstadt Dokumente” (Berlin, 1905). An inside view of club life in Berlin. (VI, 6; IX, 1, 2, 3, 4.) Lucas, Edw. V. _The Friendly Town: A Little Book for the Urbane_ (New York, 1906). (V, 1; IX, 2, 3.) Maciver, R. M. _Community; a Sociological Study, Being an Attempt to Set Out the Nature and Fundamental Laws of Social Life_ (London, 1917). Distinguishes between natural areas and communities, showing how occupational and cultural groupings enter into the political process. (IV, 3; V, 1, 2, 4; VI, 7.) Maurice, Arthur Bartlett. _The New York of the Novelists_ (New York, 1916). The New York as seen through the eyes of literary men. Park, Robert E., and Miller, H. A. _Old-World Traits Transplanted_ (New York, 1921). A study of immigrant communities. (VII, 2, 5; IX, 3, 4.) Sears, C. H. “The Clash of Contending Forces in Great Cities,” _Biblical World_, XLVIII (October, 1916), 224–31. (VII, 5; IX, 1, 3.) Symposium, “The Greatest Negro Community in the World,” _Survey Graphic_, LIII (March 1, 1925), No. 11. A collection of articles on the Negro community in Harlem, New York. (VII, 2, 3; IX, 1, 3, 4; X, 1.) Williams, Fred V. _The Hop-Heads: Personal Experiences among the Users of “Dope” in the San Francisco Underworld_ (San Francisco, 1920). (VII, 2; IX, 3, 4.) 4. The city may be graphically depicted in terms of a series of concentric circles, representing the different zones or typical areas of settlement. At the center we find the business district, where land values are high. Surrounding this there is an area of deterioration, where the slums tend to locate themselves. Then follows an area of workmen’s homes, followed in turn by the middle-class apartment section, and finally by the upper-class residential area. Land values, general appearance, and function divide these areas off from each other. These differences in structure and use get themselves incorporated in law in the form of zoning ordinances. This is an attempt, in the face of the growth of the city, to control the ecological forces that are at work. Cheney, C. H. “Removing Social Barriers by Zoning,” _Survey_, XLIV (May, 1922), 275–78. (V, 1, 5; VII, 2.) Eberstadt, Rudolph. _Handbuch des Wohnungswesens und der Wohnungsfrage_ (4th ed.; Jena, 1910). An encyclopedic work on housing, city-zoning, and planning. (VI, 1, 2, 3, 6, 7, 8, 9, 10; VII.) Kern, Robert R. _The Supercity: A Planned Physical Equipment for City Life_ (Washington, D.C., 1924). A planned model city with co-operative services of many sorts, with zoning as an important feature. (V, 5; VI.) Wuttke, R. _Die deutschen Städte_ (2 vols.; Leipzig, 1904).