Erdoes, Richard.
A.D. 1000: living on the brink of apocalypse /
Richard Erdoes 
. - San Francisco : Harper & Row, Publishers,  1988 
. - xvi, 228 p.  map., schem.  24 cm. 
<br/>К.: Бібліогр. : c. 213-221, Index 
<br/><label>  ISBN: </label>0-06-250295-6 
<br/><br/><label>Subjects--Personal Names: </label><br/>Sylvester II  Pope  ca. 945-1003