Die Lehre von der Tradition in der römischen Schule, 1962.
Kürschners Deut. Gel. Kal., 1987 (Dr. theol., Prof. Walter Kasper)
Vatican - Holy See official WWW website, viewed Sept. 8, 2006 link to Cardinals page (Walter Kasper; b. Mar. 5, 1933 in Heidenheim, Germany; proclaimed cardinal Feb. 21, 2001)