1. ^¹ {{cite book|author1=D. J. van de Kaa|author2=Kaa|author3=Y. de Roo|title=De Leden Van de Koninklijke Nederlandse Akademie Van Wetenschappen: Een Demografisch Perspectief: 1808 Tot 2008|url=https://books.google.com/books?id=gzNvCGJEGCYC|date=19 December 2008|page=320|publisher=Amsterdam University Press|isbn=978-90-6984-552-4}}
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