"In conclusion, this book is attractive for a broad readership of legal scholars, sociologists and political scientists, and can be wholeheartedly recommended to anyone with an interest in nationality and citizenship issues,whether from the national or international perspective, within or outside of the legal discipline. As nationality, and especially dual nationality, acquire a more dominant position in the discussion on migration, migration scholars from a wide range of disciplines would benefit from reading this book as well. For EU lawyers, in particular, this study offers an excellent analysis of the complex debate on the exclusivity of Member States’ competences in the field of nationality law in the light of the dynamic development of the concept of EU citizenship."Katja Swider, Common Market Law Review 50: 1505–1507, 2013.