The peerage of England, or A genealogical and historical account of all the families of this kingdom, that have born the dignity of peerage, either by tenure, summons to parliament, investiture, or creation, & c. from the conquest to this present year, 1713. Vol. II, [in 2 pt.]

Mode of access: Internet.

Quellen zur Geschichte des Investiturstreits.

1. Zur Geschichte Gregors VII. und Heinrichs IV.--2. Zur Geschichte des wormser Konkordates.

Der Sieg Heinrichs IV. in Kanossa; eine kritische Untersuchung.

Mode of access: Internet.