Ludolf Anne Jan Wilt, Baron Sloet, editor (1872), Oorkondenboek der Graafschappen Gelre en Zutfen tot op den Slag van Woeringen, 5 Juni 1288 [Book of charters of the Counties of Guelders and Zutphen up to the Battle of Woeringen, 5 June 1288], Eerste Gedeelte: Tot den dood van Graaf Gerard, 22 October 1229 (in Dutch), Gravenhage: Martinus Nijhoff, page 23: “EgoAdricharius, iussu dominimei Pippini et Plectrude, hanc donationem scripsi et subscripsi. ― I, Adricharius, by order ofmy lordPippin and Plectrude, have written and signed this donation.”