When Europeans Were Slaves: Research Suggests White Slavery Was Much More Common Than Previously Believed Archived 25 July 2011 at the Wayback Machine Archived 25 July 2011 at the Wayback Machine.
اطلع عليه بتاريخ 08 يوليو 2012.  When Europeans Were Slaves: Research Suggests White Slavery Was Much More Common Than Previously Believed نسخة محفوظة 25 July 2011 على موقع واي باك مشين..