Editors. "Prussian lands pass to the electorate of Brandenburg". The Literary Encyclopedia. First published 01 February 2011
[http://www.litencyc.com/php/stopics.php?rec=true&UID=15817, accessed 25 May 2013.]
When Albert II, Duke of Prussia, dies without heirs, his territories pass to the electorate of Brandenburg, although they remain under Polish suzerainty.