Editors. "Bonn is captured by Frederick, Elector of Brandenburg". The Literary Encyclopedia. First published 01 April 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=16834, accessed 22 May 2013.]
The German city of Bonn, which is part of the autonomous Electorate of Cologne, is captured by Frederick, Elector of Brandenburg.