Application development by endusers. - R. Kogon; E. Keppel; D. Kropp (IBM Symposium: Interactive Systems, 1976)

Interactive Programming by End-users. - E. Keppel; D. Kropp (ACM Annual Conference, 1977)

Der IBM Spracherkennungsprototyp TANGORA - Anpassung an die deutsche Sprache. - Georg Walch; K. Mohr; U. Bandara; J. Kempf; E. Keppel; Klaus Wothke (DAGM-Symposium, 1989)

The SPRING speech recognition system for German. - Klaus Wothke; U. Bandara; J. Kempf; E. Keppel; K. Mohr; Georg Walch (EUROSPEECH, 1989)