Columbia subject headings:
Artists--Germany--Correspondence.
Nölken, Franz, 1884-1918--Correspondence.
Rump, Ernst, 1872-1921--Correspondence.
Harvard subject headings:
Artists--Germany--Correspondence.
Nölken, Franz, 1884-1918--Correspondence.
Nölken, Franz, 1884-1918--Exhibitions.
Rump, Ernst--Art collections--Catalogs.
Princeton subject headings: