Columbia subject headings:
Architectural design--Germany--Cologne--Early works to 1800--Bibliography.
Columns--Germany--Cologne.
Harvard subject headings:
Architectural design--Germany--Cologne.
Architecture--Details--Handbooks, manuals, etc.
Architecture--Germany--Cologne.
Architecture--Philosophy
Columns--Germany--Cologne.
Decoration and ornament, Architectural--Germany--Cologne.
Vitruvius Pollio. De architectura--Influence.
Princeton subject headings:
Architectural design--Germany--Cologne--Early works to 1800--Bibliography.
Columns--Germany--Cologne.