APA način citiranja (7. izdanje)
ebrary, Inc, & Sack, R. D. (2002). Progress: Geographical essays. Johns Hopkins University Press.
Čikaški stil citiranja (17. izdanje)
ebrary, Inc, i Robert David Sack. Progress: Geographical Essays. Baltimore: Johns Hopkins University Press, 2002.
MLA način citiranja (9. izdanje)
ebrary, Inc, i Robert David Sack. Progress: Geographical Essays. Johns Hopkins University Press, 2002.
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