Columbia subject headings:
Industries--Germany.
Louisiana Purchase Exposition (1904 : Saint Louis, Mo.).
Harvard subject headings:
Industries--Germany
Louisiana Purchase Exposition (1904 : Saint Louis, Mo.)
Louisiana Purchase Exposition (1904 : Saint Louis, Mo.)--Germany.
Princeton subject headings:
Behrens, Peter, 1868-1940.
Industries--Germany.
Louisiana Purchase Exposition (1904 : Saint Louis, Mo.)--Germany.