Editors. "Pope Alexander VI calls on all princes to support a crusade". The Literary Encyclopedia. First published 01 November 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=14029, accessed 25 April 2014.]
Pope Alexander VI proclaims a Year of Jubilee, a year of 'forgiveness of all sins'. He also imposes a tithe on all princes by calling on their Christian duty to support a crusade against the Turks.