TY  - SER
AU  -  Petruccelli della Gattina, Ferdinando, 
TI  -  Il re dei re, vol. 3 (di 4) : :  
AV  - BX 
PY  - 2013///
PB  -  Project Gutenberg, 
KW  -  Gregory VII, Pope, approximately 1015-1085
KW  -  Church history -- 11th century
KW  -  Papacy -- History -- To 1309
N1  -  Public domain in the USA;  Text
UR  -  http://www.gutenberg.org/ebooks/44355
ER  -