.Herbert, D. T., & .Smith, D. M. (1979). Social problems and the city: Geographical perspectives. Oxford University Press.
Chicago-referens (17:e uppl.).Herbert, David T., och David M. .Smith. Social Problems and the City: Geographical Perspectives. New York : Oxford: Oxford University Press, 1979.
MLA-referens (9:e uppl.).Herbert, David T., och David M. .Smith. Social Problems and the City: Geographical Perspectives. Oxford University Press, 1979.