The origins of the Great Schism:
Ullmann, Walter
The origins of the Great Schism: a study in fourteenth-century ecclesiastical history by Walter Ullmann - London Burns, Oates & Washbourne 1948
Schism, The Great Western
The origins of the Great Schism: a study in fourteenth-century ecclesiastical history by Walter Ullmann - London Burns, Oates & Washbourne 1948
Schism, The Great Western