Editors. "Frederick the Wise of Saxony creates a rival union to the Swabian League". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14229, accessed 24 April 2014.]
Frederick the Wise, Elector of Saxony, joins the Elector Palatine, the Duke of Wurttemberg and the Margrave of Baden in the union, designed to rival the Swabian League, that they had established in 1512.