Die karolingisch-ottonischen Bauten zu Werden
Effmann's 1899 German monograph, published in Strassburg by Heitz, documents the Carolingian and Ottonian buildings at Werden, an abbey church area, for scholars of medieval church architecture. Its pictures are measured architectural drawings: sections, a ground plan with cross-vaulted bays, a crypt-like elevation with arches, and a flat exterior elevation with rows of round-headed windows, showing bay rhythm and wall construction a designer could adapt for line-art architectural motifs.
