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Donna T. Andrew, ‘Spencer , (Margaret) Georgiana, Countess Spencer (1737–1814)’, Oxford Dictionary of National Biography, Oxford University Press, 2004 accessed 17 Aug 2017. This is a subscription site but access is free to readers of British libraries whose library subscribes.
WikiTree profile Poyntz-86 created through the import of Spencer Family Tree 4 2002.GED on Nov 28, 2011 by Chet Spencer. See the Changes page for the details of edits by Chet and others.