Musicæ Scientiæ Collectanæ: Festschrift Karl Gustav Fellerer zum siebzigsten Geburtstag am 7. Juli 1972 - Fellerer, Karl Gustav 1902-1984; Hüschen, Heinrich 1915-1993 (Cologne Volk, 1973)
Contains a signed card from Fellerer to Federhofer, Cologne, July 1972