Columbia subject headings:
Book collecting--Europe--History--19th century.
Book collecting--Europe--History--20th century.
Books and reading--History--19th century.
Books and reading--History--20th century.
Books--Speciation--History--19th century.
Books--Speciation--History--20th century.
Harvard subject headings:
Books--Europe--History.
Books--Germany--History.
Books--History--19th century.
Books--History--20th century.
Princeton subject headings: