(en) S. Miles Bouton, And the Kaiser Abdicates: the German Revolution November 1918 – August 1919, Library of Alexandria, (ISBN9781465538109, lire en ligne).
thegazette.co.uk
At the Court at Buckingham Palace, the 28th day of March, 1919., His Majesty's Stationery Office, , Issue 31255, Page 4000 (lire en ligne).