Columbia subject headings:
Busch, Adolf, 1891-1952--Correspondence.
Violinists--Germany--Correspondence.
Harvard subject headings:
Busch, Adolf, 1891-1952--Correspondence.
Busch, Adolf, 1891-1952.
Violinists--Germany--Correspondence.
Princeton subject headings:
Busch, Adolf, 1891-1952--Correspondence.
Violinists--Germany--Correspondence.