Columbia subject headings:
Hercules (Roman mythological character)--Drama.
Operas--Scores.
Harvard subject headings:
Music--Manuscripts--Facsimiles
Operas--Scores
Princeton subject headings:
Heracles (Greek mythological character)--Drama.
Hercules (Roman mythological character)--Drama.
Music--Manuscripts--Facsimiles.
Operas--Scores.
Operas.
Scores.