Giolitti e i cattolici : (1901-1914) - Spadolini, Giovanni. (OLS)http://ftis/name/58873 (Arnoldo Mondadori, 1974)

Katholische Theologen der Reformationszeit - Bäumer, Remigius. (OLS)http://ftis/name/51974; Iserloh, Erwin. (OLS)http://ftis/name/51726 (Aschendorff, 1984)