This book might interest you. The Battle for Rome : The Germans, the Allies, the Partisans, and the Pope, September 1943-June 1944 by Robert Katz.
I just finished it and found it interesting. Detailed accounts of the German occupation and retaliations, partisan actions, OSS involvment, and the actions of the Pope (or lack thereof). If you are looking for a detailed account of the fight between the German occupiers and Roman Partisans you will be pleased. If you are looking for detailed accounts for the Allied battles and race for Rome look elsewhere. It is available for 10 bucks at amazon.
Regards,
WeAgs2