Columbia subject headings:
Aleatory music.
Music--Manuscripts--Facsimiles.
Quartets (Percussion, violin, viola, cello)--Scores.
Wolff, Christian, 1934---Manuscripts--Facsimiles.
Harvard subject headings:
Music--Manuscripts--Facsimiles.
Quartets (Percussion, violin, viola, cello)--Scores.
Wolff, Christian, 1934---Manuscripts--Facsimiles.
Princeton subject headings: