Folsom, Ralph Haughwout, author
West Group, 2011
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Pohan, Hazairin, author
Jurnal Kajian Wilayah Eropa, 2008
Artikel Jurnal
edited by Diamond Ashiagbor, Nicola Countouris, Ioannis Lianos
Cambridge University Press, 2012
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Kennet Lynggaard, Ian Manners, karl Lofgren, editor
Palgrave Macmillan, 2015
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edited by Maribel Gonzalez Pascual and Aida Torres Perez
Routledge, 2017
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