Smith, Thomas W. "Between two kings: Pope Honorius III and the seizure of the Kingdom of Jerusalem by Frederick II in 1225." Journal of Medieval History 41, 1 (2015): 41–59.
Smith, Thomas W. "Between two kings: Pope Honorius III and the seizure of the Kingdom of Jerusalem by Frederick II in 122?5." Journal of Medieval History 41, 1 (2015): 41–59.