Bock, E. C. (1977). Wilhelm von Ketteler, Bishop of Mainz: His life, times and ideas. University Press of America.
Chicago-referens (17:e uppl.)Bock, Edward C. Wilhelm Von Ketteler, Bishop of Mainz: His Life, Times and Ideas. Washington, D.C.: University Press of America, 1977.
MLA-referens (8:e uppl.)Bock, Edward C. Wilhelm Von Ketteler, Bishop of Mainz: His Life, Times and Ideas. University Press of America, 1977.
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