Das Katholische Frankfurt-Einst und Jetzt - Greef, Klaus. (OLS)http://semarc/name/53931 (Josef Knecht, 1989)
Fondo card. C.M. Martini (4Y IV 115)
Keywords: Francoforte sul Meno - Storia religiosa. (OLS)http://semarc/subject/54445; Cattedrali - Germania. (OLS)http://semarc/subject/23619