Clifford, T. (2009). Rourke's World of Science ENCYCLOPEDIA: Volume 4 - Earth Science. Rourke Publishing.
Čikaški stil citiranja (17. izdanje)Clifford, Tim. Rourke's World of Science ENCYCLOPEDIA: Volume 4 - Earth Science. Rourke Publishing, 2009.
MLA način citiranja (8. izdanje)Clifford, Tim. Rourke's World of Science ENCYCLOPEDIA: Volume 4 - Earth Science. Rourke Publishing, 2009.
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