Van de Logt, Mark. Ponca. (Wayback Machine saytida 2012-01-14 sanasida arxivlangan) Oklahoma Historical Society’s Encyclopedia of Oklahoma History & Culture. 2009 (8 August 2009)
Van de Logt, Mark. Ponca. (Wayback Machine saytida 2012-01-14 sanasida arxivlangan) Oklahoma Historical Society’s Encyclopedia of Oklahoma History & Culture. 2009 (8 August 2009)