Indices eorum quae Monumentorum Germaniae Historicorum tomis hucusque editis continentur / scripservunt O. Holder-Egger et K. Zeumer. - Holder-Egger, Oswald, 1851-1911. (OLS)http://pul/name/10454; Zeumer, Karl, 1849-1914. (OLS)http://pul/name/9029 (Hansche Buchhandlung, 1985)