Fichtenau, Heinrich..
Heretics and scholars in the high Middle Ages, 1000-1200 /
translated by D.A. Kaiser 
. - University Park  : The Pennsylvania State University Press,  1998 
. - VIII, 403 p.  23 cm. 
<br/>К.: Бібліогр. : с. 375-389. 
<br/><label>  ISBN: </label>0-271-01765-1