Hasler, A.B..
How the Pope Became Infallible: Pius IX and the Politics of Persuasion /
Intr. by H. Küng ; Transl. by P.Heinegg 
. - New York : Doubleday and Co.,  1981 
. - xi, 383 p.  22 cm. 
<br/><label>  ISBN: </label>0-385-15851-3