Columbia subject headings:
Humperdinck, Engelbert, 1854-1921--Bibliography--Catalogs.
Harvard subject headings:
Humperdinck, Engelbert, 1854-1921--Bibliography--Catalogs.
Humperdinck, Engelbert, 1854-1921--Bibliography.
Princeton subject headings:
Humperdinck, Engelbert, 1854-1921--Bibliography--Catalogs.