Thibault, Paul R. 1947-.
Pope Gregory XI: the failure of tradition /
Paul R. Thibault 
. - Lanham : New York : London : University Press of America,  1986 
. - 242 p.  map.  23 cm. 
<br/>К.: Бібліогр. : c. 223-237, Index 
<br/><label>  ISBN: </label>0-8191-5462-8 
<br/><br/><label>Subjects--Personal Names: </label><br/>Gregory XI  pope  1329-1378