Columbia subject headings:
Composers--Austria--Correspondence.
Composers--Correspondence.
Music--20th century--History and criticism.
Schoenberg, Arnold, 1874-1951--Correspondence.
Zemlinsky, Alexander, 1871-1942--Correspondence.
Harvard subject headings:
Composers--Austria--Correspondence
Composers--Correspondence
Music--20th century--History and criticism
Schoenberg, Arnold, 1874-1951--Correspondence.
Zemlinsky, Alexander, 1871-1942--Correspondence.
Princeton subject headings:
Berg, Alban, 1885-1935.
Composers--Austria--Vienna--Correspondence.
Schoenberg, Arnold, 1874-1951.
Schreker, Franz, 1878-1934.
Webern, Anton, 1883-1945.
Zemlinsky, Alexander, 1871-1942.