*[http://www.geocities.com/Athens/Atrium/8410/ Apologia: A Catholic Page for Protestants and Eastern Orthodox] - unknown author
*[http://www.newadvent.org/cathen/13535a.htm Catholic Encyclopedia article on the so-called "Eastern Schism"] - unknown author
*[http://www.newadvent.org/cathen/12043b.htm Catholic Encyclopedia on "Photius of Constantinople"] - Fr. Adrian Fortescue (an early 20th-century Roman Catholic liturgical scholar)
, '''brazen character assassination of St. [[Photios the Great]]'''