found: nuc88-7310: His Priesterbild und Reformpapsttum ... 1984(hdg. on MnU rept.: Laudage, Johannes; usage: Johannes Laudage)
found: Gregorianische Reform und Investiturstreit, 1993:title page (Johannes Laudage) back cover (born 1959; Dr. phil. from the Universität zu Köln)
found: Alexander III. u. Friedrich Barbarossa, 1997:title page (Johannes Laudage) spine (J. Laudage)
found: German Wikipedia, viewed October 12, 2022(Johannes Laudage; born February 23, 1959, in Menden; died January 26, 2008, in Nattenheim, in the Eifelkreis Bitburg-Prüm; German historian and medievalist; he was professor of medieval history at the Heinrich-Heine-Universität Düsseldorf)