Geschichte der Ausstattung der Kirche des heiligen Victor zu Xanten : nach den Originalbaurechnungen und anderen handschriftlichen Quellen
Stephan Beissel's 1887 German study, published by Herder in Freiburg im Breisgau, traces the furnishings of the St Victor church (Dom) at Xanten from original building accounts and manuscript sources. The pictures are lettered and numbered floor plans of the church's chapels, choir stalls and altars, drawn in plain black outline with no shading. A designer could take from them a clear diagrammatic language of plan labelling, with letters and numerals keyed to a legend, useful for layout or wayfinding schemes.
