Zoepfl, Heinrich (1844). Deutsche Staats- und Rechtsgeschichte: Ein Lehrbuch in zwei Bänden (in German). Vol. Erster Band (2nd expanded & improved ed.). Stuttgart: Verlag von Adolph Krabbe. p. 30.; Larned, Josephus Nelson; Reiley, Alan C. (1895). History for ready reference. Springfield, Ma.: The C. A. Nichols Co., Publishers. p. 1435.; corresponding to an Anglo-Saxon word, hreopseta, "settlement on a bank (or river)." The -waren would be from Germanic *weraz, "people" Köbler, Gerhard (2000). "*uei-(3)"(PDF). Indogermanisches Wörterbuch (in German) (3rd ed.).
The -wehren would be from Germanic *warjan, "defend," Köbler, Gerhard (2000). "*uer-(5)"(PDF). Indogermanisches Wörterbuch (in German) (3rd ed.).
Köbler, Gerhard (1993). "Rifera"(PDF). Althochdeutsches Wörterbuch (in German) (4th ed.).
