Briefwechsel 1934-1988 - Pieper, Josef, 1904-1997. (OLS)http://ftis/name/61230; Wald, Berthold. (OLS)http://ftis/name/71024; Balthasar, Hans Urs : von, card., 1905-1988. (OLS)http://ftis/name/51283 (Johannes Verlag, 2025)