ebrary, Inc, Bennett, R. J., & Estall, R. C. (1991). Global change and challenge: Geography for the 1990s. Routledge.
Chicago-viite (17. p.)ebrary, Inc, R. J. Bennett, ja Robert C. Estall. Global Change and Challenge: Geography for the 1990s. London ; New York: Routledge, 1991.
MLA-viite (9. p.)ebrary, Inc, et al. Global Change and Challenge: Geography for the 1990s. Routledge, 1991.
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